GIFT   OF 
W  T3 


uf.  (-A/Ce^? 


Youf  attention  is  called  to  the  new  and  revised  edition  of 
ELDERHORST'S   MANUAL 

OP 

BLOW-PIPE    ANALYSIS 

AND 

DETERMINATIVE     MINERALOGY, 

JUST    ISSUED. 

PHILADELPHIA,  APRIL  4,  1866. 

The  present  edition  will  be  found  to  contain  a  great  deal  of  additional  valuable 
matter,  the  result  of  several  years'  experience,  (since  the  first  edition,)  both  in  the 
Laboratory  and  the  Lecture  Room,  which  enables  us  to  give  a  useful  Manual  for  both 
Teachers  and  Students. 

We  will  briefly  recite  some  of  the  additions  of  special  interest  to  those  who  may  us« 
the  blow-pipe  ns  an  aid  to  the  study  of  Mineralogy. 

In  the  Fourth  Chapter  the  Author  has  given  the  characteristic  physical  properties, 
blow-pipe  reactions,  and  behavior  to  solvents  of  all  the  important  Ores  of  the  useful 
metals,  so  that  a  reference  to  this  chapter  will  at  once  enable  the  student  or  the 
practical  mineralogist  and  geologist  to  determine  the  nature  and  mineral  species  of 
the  Ore  under  examination.  But  not  only  the  mineral  species  can  thus  be  easily 
ascertained;  by  referring  to  the  methods  laid  down  in  the  Third  Chapter  for  the  de 
tection  of  metallic  oxides,  Ac.,  in  presence  of  other  compounds,  incidental  constituents, 
such  as  silver  in  galena,  nickel  in  cobaltine,  can  be  discovered  without  difficulty. 
The  Sixth  Chapter  contains  Prof,  von  Kobell's  method  for  the  discrimination  of  min 
erals  by  means  of  the  blow-pipe,  aided  by  humid  analysis.  It  is  unnecessary  to  dwell 
on  its  merits, 'as  it  is  almost  universally  acknowledged  to  be  the  best  guide  for  the 
discrimination  of  minerals  that  has  ever  been  published. 

The  appended  tables,  containing  the  behavior  of  the  alkaline  earths,  the  earth? 
proper,  and  the  oxides  of  the  heavy  metals  before  the  blow-pipe  and  to  the  most  im 
portant  reagents,  have  been  taken  from  Plattner's  work  on  the  blow -pipe,  the  most 
thorough  treatise  on  the  subject. 

We  are  happy  to  be  able  to  give  below,  the  opinions  of  some  of  our  scientific  men  : 

From  GKOROK  J.  BRUSH,  Professor  of  Mineralogy  and  Metallurgy  in  Yale  College.  (Scientific 

Department.) 

"The  second  edition  of  Prof.  EllerltnrsPs  Manual  of  Blow-pipe  Analysis  will  be  warmly  wel 
comed  by  all  students  of  Chemistry  and  Mineralogy.  It  fills  a  want  very  much  felt  by  both 
teachers  and  students,  and  as  the  present  edition  contains  not  only  a  thorough  treatise  on  Qualita 
tive  Blfnv-pipe  Analysis,  but  also  an  extended  chapter  on  Determinative  Mlneral<>(jy,  this  last 
extracted  from  Von  Kobell's  excellent  TaftJn  zur  Bf.stimmnng  der  Minernlifn.  it  forms  a  most 
invaluable  manual  for  the  Laboratory  and  Cabinet.  I  have  for  several  years  used  the  first  edition 
as  a  text-book  for  my  students,  and  have  found  it  a  most  useful  and  accurate  work.  I  shall  most 
willingly  adopt  this  new  and  enlarged  edition,  and  I  take  pleasure  in  cordially  recommending  it  to 
all  teachers  and  students  of  Chemistry  and  Mineralogy." 


From  CHARLES  A.  JOT,  PH.  D..  Professor  of  Chemistry  in  Columbia  College,  New  York. 
"I  am  greatly  pleased  with  the  improved  appearance  of  this  edition.    It  is  now  the  most  con 
venient  work  on  the  blow-pipe  we  have,  and  I  shall  recommend  it  to  all  of  my  friends.    All  of  my 
pupils  who  have  used  it,  have  made  remarkable  progress  in  the  detection  of  metals,  and  iu  tho 
determination  of  minerals." 

0) 


From  Professor  JAMES  C.  BOOTH,  (Clicmist,)  Melter  and  Refiner,  Unite'd  States  Mint. 
"After  a  careful  examination  of  Elderliorsfs  Slow-pipe  Analysis,  which  you  have  recently  pub 
lished,  I  am  of  opinion  that  it  is  the  best  treatise  on  the  subject  for  the  .use  of  beginners  and 
students,  and  that  the  experienced  chemists  will  find  in  it  an  invaluable  vademccum  in  testing 
minerals  and  inorganic  bodies  generally.  I  shall  therefore  recommend  it  to  others  and  use  it 
myself."  ^-  ""£_ 

*"  i- 

From  Dr.  WOI.COTT  GIBES,  Professor  of  Chemistry  in  the  Free  Academy,  New  York. 

"  I  most  cordially  approve  of  the  plan  andiexecution  of  the  treatise,  and^sincerely  hope  that  it« 
sale  may  be  commensurate  with  its  merits.  It  is  a  most  welcome  and  useful  addition  to  our 
scientific  literature."  j 


From  Prof.  B.  HOWARD  RAND,  M.  D.,  Professor  of  Chemistry  in  the  Jefferson  Medical  College, 
Philadelphia. 

Late  Professor  of  Chemistry  in  the  Medical  Department,  Pennsylvania  College; 

Franklin  Institute; 

and  Physics  in  the  Philadelphia  Central  High  School. 

"I  can  most  cordially  commend  Dr.  Elderhorsfs  Manual  of  Blow-pipe.  Analysis.  It  is  clear, 
concise  and  accurate,  and  I  shall  take  pleasure  in  recommending  it  to  my  classes  as  the  best 
elementary  work  on  the  subject." 

From  Dr.  F.  A.  GEN  in. 

"CHEMICAT.  LABORATORY,  PHILADELPHIA. 

"  Dr.  Eldcrliorst"  s  Manual  of  Blow-pipe  Analysis  and  Determinative  Mineralogy,  just  issued  by 
you,  is  the  most  convenient  work  of  this  kind  in  the  English  language,  and  I  shall  use  it  as  a  text 
book  for  my  students,  and  with  great  pleasure  recommend  it  most  cordially  to  all  my  friends  who 
are  engaged  in  chemical  and  mineralogical  pursues." 

From  CHARLES  P.  WILLIAMS,  Analytical  and  Consulting  Chemist. 

PHILADELPHIA  March  24,  1866. 

"I  regard  Elderhorsfs  Manual  nf  Blow-pipe  Analysis  as  the  most  convenient  elementary  text 
book  in  the  English  language  for  the  student  of  determinative  mineralogy,  and  as  such,  for  several 
years  have  recommended  it  to  students  in  my  laboratory.  Though,  concise  and  condensed,  no 
necessary  elaboration  of  detail  has  been  omitted,  and  it  is  as  usefirl%-to  the  preceptor  as  to  the 
utudent.  I  recommend  it  with  great  pleasure." 

SCHOOL  OF  MINES,  COLUMBIA  COLLEGE,  N.  Y.,-5Iarch  14,  1S66. 

THOMAS  EGLKSTON,  Jr.,  A.M.,  E.M.,  Professor  of  Mineralogy  and.  Metallurgy,  says: — "We  hav« 
always  used  Elderhorsfs  Manual  for  the  Blow-pipe,  in  preference  to  any  other." 

From  CHARLES  F.  CHANDLER,  PH.  D.,  Professor  of  Analytical  and  Applied  Chemistry,  and  Dean  of 
Faculty,  Columbia  College,  N.  Y. 

"  NEW  YOBK,  March  24, 1866. 

"  I  am  very  glad  to  learn  that  you  intend  publishing  a  new  edition  of  Elder liorsfs  Blow-pip* 
Analysis.  As  a  text-book  for  students  in  blow-pipe  analysis,  and  the  discrimination  of  mineral* 
by  their  chemical  reactions,  it  is  far  superior  to  any  other  book  in  our  language." 

From  SILAS  II.  DOUGLASS,  Professor  of  Chemistry  and  Mineralogy. 

"  UNIVERSITY  OF  MICHIGAN,  DEPARTMENT  OF  Cn>  MISTRY,  March  28, 1866. 

"I  am  glad  to  hoar  that  you  are  about  to  issue  a  new  edition  of  Elderhorst  on  the  Blow-pipe. 
"  Having  used  it  for  several  years  as  a  text-book  with  my  classes.  I  do  not  hesitate  to  say  that 
I  know  of  no  work  capable  of  taking  its  place  in  the  Laboratory  of  Determinative  Mineralogy." 

From  A.  B.  PRESCOTT,  M.D.,  Asst.  Prof,  of  Chemistry,  and  Lecturer  on  Metallurgy. 

"CHEMICAL  LABORATORY  of  the  UNIVERSITY  OF  MICHIGAN,  March  L'6,  18G6. 

"I  esteem  Elderliorst's  Blowpipe  Analysis  as  the  best  Manual  extant  for  the  student  in  Deter 
minative  Mineralogy.  The  systematic  tabular  methods  of  Analysis,  in  the  fifth  and  sixth 
chapters  of  the  2d  edition,  are  efficient  aids  in  complete  chemical  examination.  Having  been  at 
some  inconvenience  from  its  having  been  recently  out  of  print,  I  shall  gladly  welcome  a  new 
edition." 

From  Professor  WILLIAM  B.  RISING,  Michigan  University. 

"  FEBRUARY  22, 1866. 

"Our  school  of  mines  is  just  starting.  We  shall  use  ElderlinrsCs  Manual.  I  have  yet  to  find 
the  man  who  will  say  that  it  is  not  the  standard  work  for  a  beginner  in  blowpiping." 


Price  of  the  Manual,  sent  per  mail,  prepaid,  $2.50. 

Respectfully, 

T.    ELLWOOD    ZELL,    Publisher, 

17  &  19  South  Sixth  Street,  Philadelphia. 


A   MANUAL 


OP 


BLOW-PIPE  ANALYSIS. 


DETERMINATIVE  MINERALOGY. 


BY 

WILLIAM   ELDERHOPvST,  M.D., 

PROFESSOR     OF     CHEMISTRY     IS     THE     RENSSELAER     POLYTECHNIC     INSTITUT*. 


®hird  (Edition, 

EEV1SED     AND     GREATLY      ENLARGED, 


PHILADELPHIA: 
T.    ELLWOOD    ZELL, 

N03.  17  AND  19  SOUTH  SIXTH  STREET. 

1866. 


Entered  according  to  Act  of  Congress,  in  the  year  1866,  by 
T.   ELLWOOD    ZELL, 

in  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for  the  Eastern  District 
of  Pennsylvania. 


(iT) 


PRINTED  BY  SMITH  &  PETERS, 

Franklin  Buildings,  Sixth  Street,  below  Arch, 

Philadelphia. 


PREFACE. 


THE  present  edition  of  this  "Manual"  is,  like  the  preceding, 
designed  to  serve  as  a  text-book  in  the  instruction  in  Blowpipe- 
Analysis  and  Determinative  Mineralogy,  in  the  Itensselaer 
Polytechnic  Institute. 

In  the  first  three  chapters,  but  few  alterations  and  additions 
have  been  made,  fearful  of  injuring  the  practical  usefulness  of 
the  book  by  an  accumulation  of  too  much  material.  The  fourth 
chapter,  containing  the  characteristics  of  the  most  important 
ores,  has  been  considerably  enlarged  by  increasing  the  number 
of  species,  and  by  adding  an  appendix  containing  the  descrip 
tion  and  blowpipe-reactions  of  the  various  kinds  of  fossil  fuel; 
additions  which,  I  trust,  will  be  especially  acceptable  to  the 
Mining-Engineer  and  Geologist.  In  the  selection  of  the  newly 
added  species  I  have  paid  particular  regard  to  those  occurring 
in  the  American  Continent;  for  this  reason,  many  less  impor 
tant  ores  have  found  a  place  in  the  list  to  the  exclusion  of  others, 
which,  though  more  valuable,  have  not  hitherto  been  found  in 
America. 

The  fifth  chapter,  containing  a  systematic  method  for  the 
discrimination  of  inorganic  compounds,  is  a  translation,  but 
filightly  altered,  of  the  "  Division  dichotomique  pour  reconnaitre  les 
mineraux"  as  given  in  Laurent's  '-'•Analyze  au  Chalumeau."  It  is 
of  no  great  value  to  the  experienced  analyst,  but  very  useful 
for  beginners,  and  it  is  on  their  account  that  I  have  given  it  a 
place  in  the  Manual. 

The  sixth  chapter  is  not  contained  in  the  first  edition.  It  is 
hardly  necessary  to  allege  any  reason  for  its  introduction  into 

l*  237534  (T) 


VI  PREFACE. 

this  edition.  The  admirable  method  of  Professor  von  Kobell 
for  the  discrimination  of  minerals  is,  almost  beyond  dispute,  the 
most  practical  and  most  reliable  that  has  ever  been  published. 
The  sixth  chapter  is  nothing  but  an  extract  from  Prof.  v.  Ko- 
bell's  treatise  on  this  subject.  It  contains  all  the  well-known 
mineral  species,  and  leads  to  their  determination  with  almost 
unerring  certainty. 

The  appended  tables,  taken  from  Plattner's  work  on  the 
Blowpipe,  have  remained  unchanged. 

For  the  material  of  this  compilation,  the  author  is  principally 
indebted  to  the  following  works: 

C.  F.  Plattner :  The  Use  of  the  Blowpipe  in  the  Examination 
of  Minerals,  Ores,  &c.     Translated  by  J.  S.  Musprath. 
3d  ed.  London. 
J.  J.  Berzelius :  The  Use  of  the  Blowpipe  in  Chemistry  and 

Mineralogy.     Translated  by  J.  D.  Whitney.   Boston. 
F.  von  Kobell:  Tafeln  zur  Bestimmung  der  Mineralien.     5th 

ed.     Munchen,  1853. 
J.  D.  Dana  :   A  System  of  Mineralogy.     4th  ed.    New  York, 

1854. 

John  Mitchell :  Manual  of  Practical  Assaying.     2d  ed.  Lon 
don,  1854 

The  author,  finally,  begs  to  tender  his  thanks  to  his  friend, 
Professor  Chandler,  of  Union  College,  for  the  valuable  sugges 
tions  he  has  received  at  his  hands,  and  which  he  has  acted  upon 
to  the  best  of  his  ability,  being  fully  convinced  that  by  adding 
the  improvements  recommended  by  his  friend,  the  practical 
utility  of  this  little  Manual  will  be  greatly  increased. 

WILLIAM  ELDEEHOEST. 
TROF,  N.Y., 


INTRODUCTION. 


IN  preparing  this  little  Manual,  it  has  been  my  principal  care 
to  adapt  it  to  the  use  of  the  beginner.  The  use  of  the  blow-pipe, 
though  elaborately  studied  and  extensively  written  on  by  some 
of  the  first  chemists  and  mineralogists  of  the  preceding  and  the 
present  centurjr,  has  not  yet  been  duly  appreciated.  This 
neglect  is,  perhaps,  owing  to  the  rapid  advancement  of  chemi 
cal  analysis  in  the  humid  way,  which  furnishes,  on  the  whole, 
more  reliable  results,  and  allows  of  an  easy  quantitative  deter 
mination  of  the  various  constituents  of  a  body.  But  it  was  over 
looked  that  this  mode  of  analysis  absorbs  much  more  time,  and 
requires  the  use  of  an  extensive  set  of  apparatus,  whereas  an 
examination  before  the  blow-pipe  is  sooner  performed ;  requiring 
scarcely  as  many  hours  as  an  examination  in  the  humid  way 
requires  days,  and  that  with  the  aid  only  of  a  few  reagents  and 
instruments  of  small  size.  It  is  for  this  reason  that  a  knowl 
edge  of  blow-pipe  operations  is  less  valuable  for  the  Chemist  by 
profession  than  for  the  Mining-Engineer,  the  Mineralogist,  and 
the  Geologist.  A  small  portable  box  will  hold  all  the  necessary 
reagents  and  instruments,  so  that  he  may  carry  them  with  him 
on  his  expeditions  and  travels,  and  examine  on  the  spot  the 
minerals  which  he  meets  with  on  his  explorations ;  an  advan 
tage  which  ought,  truly,  not  to  be  overlooked. 

For  teachers  who  have  not  hitherto  devoted  much  time  to 
instruction  in  this  department,  a  short  exposition  of  the  course 
which  I  have  followed  for  a  number  of  years  may,  perhaps,  be 
desirable.  For  elementary  instruction,  the  students  are  only 

(Til) 


Vl  INTRODUCTION. 

furnished  with  the  principal  reagents,  viz.:  carbonate  of  soda, 
salt  of  phosphorus,  borax,  and  solution  of  cobalt;  of  apparatus 
they  want  a  fluid-lamp,  blow-pipe  with  platinum  point,  platinum- 
pointed  forceps,  platinum  wire,  charcoal,  and  closed  and  open 
glass  tubes.  After  having  explained  to  them  the  action  of  the 
two  cones  of  the  flame,  and  instructed  them  in  making  beads, 
and  conducting  the  processes  of  oxidation  and  reduction,  I 
make  them  perform  the  most  important  operations,  and  study 
the  behavior  of  the  most  commonly  occurring  substances,  with 
and  without  fluxes.  I  give  the  substances  in  somewhat  the 
following  order : 

Sesquioxide  of  iron,  all  the  reactions  given  in  Table  II,  10. 

Peroxide  of  manganese,  Table  II,  13. 

Sesquioxide  of  chromium,  Table  II,  G. 

Oxide  of  cobalt,  and  nickel,  Table  II,  7,  16. 

Protoxide  of  copper,  Table  II,  8,  and  §  37. 

Oxide  of  zinc,  Table  II,  27,  and  metallic  zinc  §§  25,  45. 

Oxide  of  tin,  Table  II,  22,  and  metallic  tin  §  20. 

Oxide  of  lead,  Table  II,  12,  and  metallic  lead  §  23. 

Oxide  of  bismuth,  Table  II,  3,  and  metallic  bismuth  §§  17,  22. 

Antimoniousacid,  Table  II,  1,  and  metallic  antimony  §§  16,  21. 

Arsenous  acid,  Table  IT,  2,  §§  9,  15. 

Oxide  of  mercury,  Table  II,  14. 

Alumina,  Table  I,  5,  and  §44. 

Magnesia,  Table  I,  4,  and  §  44. 

Silica,  §  39. 

A  sulphide,  §§10,  14.  107. 

A  borate,  §  60. 

A  chloride,  §§  65,  66. 

Having  performed  all  these  operations,  the  student  will  be 
qualified  to  enter  upon  the  analysis  of  substances  of  not  too 
compound  a  character.  If  he  meets  on  his  way  with  bodies, 
the  behavior  of  which  before  the  blow-pipe  he  has  not  pre 
viously  studied,  he  will  not  have  any  difficulty  in  determining 
their  character  if  he  follows  the  directions  given  in  the  second 
chapter.  The  modus  opcrandi  will  be  best  understood  by  a  few 
examples. 


INTRODUCTION.  1* 

1.  The  substance  under  examination  is  sulphide  of  antimony. 
Examination  in  a  matrass :  At  a  very  high  temperature,  a 

black  sublimate  is  obtained,  becoming  reddish-brown  when 
cold.  In  reading  over  the  list  in  §  10,  we  find  this  character 
belonging  to  sulphide  of  antimony. 

Examination  in  an  open  glass  tube :  gives  sulphurous  acid 
detected  by  the  odor  and  action  on  blue  litmus-paper,  and 
white  fumes  which  partly  condense  in  the  tube.  On  examining 
the_sublimate  with  a  magnify  ing-glass,  it  is  found  to  be  amor 
phous,  hence  must  be  antimonious  acid  (§  16). 

Examination  on  charcoal  alone :  is  completely  volatilized 
with  emission  of  sulphurous  acid,  and  deposits  a  white  vola 
tile  coating,  possessing  the  properties  of  the  coating  of  anti 
mony  (§  21). 

These  few  operations  are  quite  sufficient  to  establish  the 
nature  of  the  substance  under  trial,  since  the  absence  of  the 
more  fixed  metals  is  proved  by  the  volatility  of  the  substance 
on  charcoal  and  in  the  open  tube,  and  the  absence  of  metals 
giving  coatings  by  the  purity  of  the  antimony-coating.  The 
presence  of  arsenic  would  have  been  betrayed  by  an  alliaceoua 
odor  when  heated  on  charcoal.  The  only  substance  which 
would  have  escaped  detection  by  these  operations  is  sulphide 
of  mercury.  In  order  to  ascertain  its  presence  or  absence,  we 
perform  the  operation  given  under  "Mercury"  in  Chapter  III. 

The  result  giving  an  answer  in  the  negative,  the  body  was 
"sulphide  of  antimony." 

2.  The  substance  under  examination  is  chromate  of  lead. 

Examination  in  a  matrass:  }  fuses  and  changes  color,  but 
Examination  in  an  open  .tube  :  j  gives  nothing  volatile. 

Examination  on  charcoal  alone:  fuses,  gives  small  metallic 
globules,  and  deposits  a  Coating  which  is  lemon-yellow  while 
hot,  and  sulphur-yellow  when  cold,  indicative  of  lead  (§23). 
It  is  always  desirable  to  collect  the  metal  to  a  large  globule, 
and  to  study  its  physical  properties.  This  end  is  best  attained 
by  mixing  the  substance  with  carbonate  of  soda  and  a  little 
borax,  and  exposing  the  mixture  to  the  reduction-flame  on. 


x  INTRODUCTION:. 

charcoal.  In  this  particular  case,  a  metallic  button  is  obtained 
which  is  soft,  may  be  flattened  by  the  hammer  and  cut  by  the 
knife,  properties  belonging  to  metallic  lead. 

Examination  with  borax  and  salt  of  phosphorus :  Before  pro 
ceeding  with  this  examination  it  is  necessary  to  test  the  sub 
stance  for  the  presence  of  sulphur  after  the  method  given  §  107 
(unless  the  presence  of  this  element  was  detected  by  the  exami 
nation  in  the  open  glass  tube  or  on  charcoal  alone);  no  sulphur 
being  present,  borax  and  salt  of  phosphorus  beads  are  made  on 
charcoal,  and  small  portions  of  the  substance  added.  With 
both  fluxes  nearly  the  same  reactions  are  obtained;  in  oxyda- 
tion-flame  dark-red  while  hot,  and  fine  yellowish-green  when 
cold  ;  in  reduction-flame  green,  hot  and  cold.  In  order  to  find 
out  what  body  produces  such  reactions,  we  use  Table  III,  which 
leads  us  to  sesquioxide  of  chromium.  To  corroborate  the  result, 
the  substance  may  be  fused  with  carbonate  of  soda  and  nitre, 
a$  described,  §  68. 

The  physical  properties  of  the  body  under  trial  lead  to  the 
final  conclusion  that  it  must  be  chromate  of  lead. 
,  3.  The  substance  is  an  alloy  of  silver,  copper,  and  lead. 

Examination  in  a  matrass  :         ) 

,   i        t  no  change. 
Examination  in  an  open  tube  :    ) 

Examination  on  charcoal  alone  :  fuses  and  deposits  a  copious 
coating,  which  is  lemon-yellow  while  hot  and  sulphury ellow 
when  cold,  indicative  of  lead  (§  23);  the  coating  cannot  contain 
any  oxide  of  bismuth,  because  the  color  would  be  darker  in 
this  case,  but  might  contain  oxide  of  zinc  or  oxide  of  antimony. 
The  test  is  for  the  presence  of  the  former,  the  coating  is  played 
upon  with  the  oxydation-flamc  :  it  is  completely  volatile,  hence 
no  zinc  present  (might  also  be  tested  with  solution  of  cobalt' 
§  45) ;  to  test  the  coating  for  the  presence  of  oxide  of  antimony, 
it  is  scraped  off  from  the  charcoal  and  dissolved  in  a  bead  of 
salt  of  phosphorus,  v.  §  87,  or  the  alloy  is  treated  with  boracic 
acid  as  described  under  the  head  of  "Antimony"  in  Chapter  III. 
If  the  blast  is  continued  for  a  long  time,  a  faint  dark-red  coat 
ing  is  formed  near  the  assay-piece,  indicative  of  silver,  §  27,  and 
n  dark  metallic  globule  remains. 


INTRODUCTION.  XI 

Examination  with  borax  and  salt  of  phosphorus  :  the  globule 
remaining  on  the  charcoal  after  volatilization  of  the  lead,  is 
treated  with  borax  on  charcoal  in  oxidation-flame  ;  the  borax 
becomes  colored.  Owing  to  the  reducing  effect  of  the  charcoal, 
the  influence  of  the  oxidation-flame  cannot  be  well  observed  on 
charcoal,  hence  the  borax  is  removed  from  the  metallic  globule, 
fastened  into  the  hook  of  a  platina  wire,  and  here  exposed  to 
the  action  of  the  oxidation-flame  :  the  bead  is  green  while  hot, 
and  blue  when  cold.  On  consulting  Table  III  we  find  that  this 
reaction  is  produced  by  oxide  of  copper,  and  by  a  mixture  of 
oxide  of  cobalt  and  sesquioxide  of  iron  :  to  decide  between  the 
two,  we  now  expose  the  bead  to  the  action  of  the  reduction- 
flame  ;  it  becomes  red  and  opaque,  thus  proving  the  presence 
of  oxide  of  copper. 

By  the  examination  on  charcoal,  per  se,  we  were  led  to  sus 
pect  the  presence  of  silver;  in  order  to  establish  this  beyond  a 
doubt,  we  refer  to  Chapter  III,  "  Silver;"  here  we  find  a  method 
(§  105)  by  which  the  presence  of  silver  may  be  ascertained  in 
compounds  of  all  descriptions.  In  our  case,  having  to  deal  only 
with  lead,  copper,  and  silver,  the  treatment  with  vitrified 
boracic  acid  and  metallic  lead  is,  of  course,  superfluous.  We 
place  our  alloy  at  once  on  the  cupel  and  direct  the  oxidation- 
flame  upon  it  ;  if,  after  cessation  of  the  rotatory  motion,  the 
globule  should  not  possess  the  bright  lustre  of  silver,  some 
pure  metallic  lead  has  to  be  added,  in  order  to  remove  the  last 
traces  of  copper.  We  finally  obtain  a  bright  globule  exhibiting 
all  the  characteristic  properties  of  silver. 

Thus  we  have  established  the  presence  of  lead,  copper,  and 
silver. 

4.  The  substance  under  examination  is  copper  nickel,  con 
taining  arsenic,  sulphur,  nickel,  cobalt,  and  iron. 

Examination  in  a  matrass  :  gives  a  slight  sublimate,  consist 
ing  of  octahedral  crystals,  pointing  to  the  presence  of  arsenic 


Examination  in  a  glass  tube  open  at  both  ends  i  gives  a  co 
pious  crystalline  sublimate  of  arsenous  acid,  and  a  faint  odor 
of  sulphurous  acid;  to  establish  the  presence  of  sulphur  beyond 


Xll  INTRODUCTION. 

doubt,  \ve  refer  to  Chapter  III,  "Sulphur,"  where  we  find  the 
method  (§  107)  for  discovering  sulphur  when  in  combination 
with  other  substances.  In  performing  the  test  there  described, 
we  obtain  the  sulphur-reaction. 

Examination  on  charcoal  alone:  gives  abundant  arsenical 
fumes,  leaving  a  metallic  globule  which,  even  with  continued 
blowing,  does  not  give  rise  to  the  formation  of  a  coating  on  tho 
charcoal  (absence  of  volatile  metals). 

Having  removed  all  volatile  substances,  we  now  proceed  to 
examine  the  remaining  globule.  On  applying  a  magnet, -we 
find  it  powerfully  attracted,  showing  the  presence  of  either 
iron,  nickel,  or  cobalt,  perhaps  all  of  them,  either  alone  or  com 
bined  with  other  non-volatile  metals.  We  add  some  borax  to 
the  globule  and  expose  it  to  the  action  of  the  oxidation-flame, 
then  remove  the  borax  from  the  globule,  fasten  it  into  the  hook 
of  a  platina  wire,  and  here  observe  the  color:  green  while  hot, 
blue  when  cold  as  in  the  preceding  case  (example  3),  but  on 
exposing  the  bead  to  the  action  of  the  reduction-flame  (which 
is  best  done  by  placing  it  on  charcoal  and  touching  it  with  tin) 
it  does  not  become  brown  and  opaque,  showing  therefore  the 
presence  of  a  small  quantity  of  iron  with  cobalt.  We  now  add 
a  "fresh  portion  of  borax  to  the  metallic  globule,  in  order  to  see 
whether  it  consists  entirely  of  cobalt  (that  it  cannot  contain 
any  considerable  amount  of  iron,  is  proved  by  the  appearance 
of  the  cobalt  reaction  in  the  first  trial,  iron  being  much  more 
readily  dissolved  by  borax  than  cobalt):  the  bead  is  violet 
while  hot,  and  assumes  a  brownish  color  on  cooling;  by  refer 
ring  to  Table  III,  we  see  that  this  effect  is  produced  by  nickel 
containing  cobalt.  Referring  to  Chapter  III,  "  Nickel."  we  find 
the  method  to  detect  the  presence  of  this  metal  when  in  com 
bination  with  iron  and  cobalt,  and  also  the  presence  of  copper, 
if  the  assay  should  contain  a  small  quantity  of  it. 

By  the  above  examples  the  use  of  the  methods  given  in  tho 
third  chapter  will  be  sufficiently  illustrated.  If  the  substance 
under  examination  is  of  a  simple  composition,  its  nature  is 
readily  ascertained  by  following  the  general  method  laid  down 
in  the  second  chapter;  but  if  the  reactions  obtained  clearly 


INTRODUCTION.  Xlll 

point  to  the  complex  nature  of  the  body,  we  refer  to  the  respec 
tive  sections  of  Chapter  III;  if,  for  example,  we  suspect  the 
presence  of  cobalt  in  a  mineral  consisting  of  arsenides,  we  test 
the  substance  according  to  §  69;  if  a  small  quantity  of  copper 
is  to  be  discovered  in  a  mineral,  we  proceed  as  directed  in 
§  71,  &c. 

The  student  who  is  willing  to  devote  more  time  to  the  sub 
ject  than  is  usuall}'  allotted  to  it  in  our  colleges,  will  do  well  to 
go  carefully  through  all  the  reactions  given  in  the  second  chap 
ter,  and  thus  familiarize  himself  with  the  colors  and  other 
properties  of  the  various  coatings,  sublimates,  £c.,  and  also  to 
perform  the  principal  tests  by  which  substances  are  discovered 
when  in  combination  with  others,  which  are  at  length  exposed 
in  the  third  chapter.  In  order  to  obtain  characteristic  reac 
tions,  it  is  important  to  experiment  upon  a  suitable  substance. 
For  the  benefit  of  the  beginner,  who  would  naturally  be  em 
barrassed  in  the  choice  of  a  body  suitable  for  the  experiment,  I 
add  a  list  of  substances  which,  with  few  exceptions,  are  readily 
obtained,  and  which  are  sufficient  to  illustrate  all  the  important 
reactions.  After  having  mentioned  a  reaction,  or  described  a 
process  (in  Chapter  II  and  III),  I  have  added  a  number  in  [  ] 
brackets.  The  number  points  to  the  substance  of  the  list, 
below  given,  best  adapted  to  illustrate  the  reaction.  As  each 
experiment  requires  only  a  very  small  quantity  of  the  sub 
stance,  they  are  most  conveniently  kept  in  small  glass  tubes  of 
about  an  inch  and  a  half  in  length  and  one-eighth  of  an  inch 
in  diameter.  For  the  first  fourteen  substances  no  glass  tubes 
are  required,  since  they  are  the  regular  blow-pipe  reagents.  A 
small  box  containing  seventy-five  of  the  little  tubes  will  hold 
the  whole  collection. 
2 


COLLECTION  OF  SUBSTANCES, 


Well  adapted  to  illustrate  the  important  Reactions  of  Bodies  before 
the  Blowpipe. 


1.  Carbonate  of  soda. 

2.  Borax. 

3.  Salt  of  phosphorus. 

4.  Bisulphate  of  potassa. 

5.  Boracic  acid. 

6.  Fluor  spar. 

7.  Nitrate  of  cobalt. 

8.  Oxalate  of  nickel. 

9.  Oxide  of  copper. 

10.  Chloride  of  silver. 

11.  Lead. 

12.  Iron. 

13.  Tin. 

14.  Bone-ash. 

15.  Chloride  of  potassium. 

16.  Bromide  of  potassium. 

17.  Iodide  of  potassium. 

18.  Chloride  of  sodium. 

19.  Chloride  of  ammonium. 

20.  Chlorate  of  potassa. 

21.  Alumina. 

22.  Sulphate  of  copper. 

23.  Nitrate  of  lead. 

24.  Oxide  of  antimony. 

25.  Arsenous  acid. 


26.  Oxide  of  bismuth. 

27.  Oxide  of  cadmium. 

28.  Sesquioxide  of  chromium. 

29.  Oxide  of  cobalt. 

30.  Protoxide  of  mercury. 

31.  Molybdic  acid. 

32.  Oxide  of  silver. 

33.  Binoxide  of  tin. 

34.  Tungstic  acid. 

35.  Sesquioxide  of  uranium. 

36.  Oxide  of  zinc. 

37.  Chloride  of  copper. 

38.  Arsenite  of  copper. 

39.  Subchloride  of  mercury. 

40.  Protochloride  of  mercury. 

41.  Antimony. 

42.  Arsenic. 

43.  Bismuth. 

44.  Cadmium. 

45.  Silver. 

46.  Zinc. 

47.  Alloy  of  mercury  and  tin. 

48.  Alloy  of  lead  and  antimony. 

49.  Alloy  of  lead  and  bismuth. 

50.  Alloy  of  lead  and  zinc. 

(xiv) 


COLLECTION    OF    SUBSTANCES. 


XV 


51.  Alloy  of  lead,  copper,  and  silver. 

72.  Cerusite. 

52.  Alloy  of  tin  and  copper. 

73.  Malachite. 

53.  Alloy  of  zinc  and  cadmium. 

74.  Gray  antimony. 

54.  Rock  crystal. 

75.  Iron  pyrites. 

55.  Gypsum. 

76.  Copper  pyrites. 

56.   Calc-spar. 

77.  Mispickel. 

57.  Strontianite. 

78.  Smaltine. 

58.  Whitherite. 

79.  Cobaltine. 

59.  Magnesite. 

80.  Realgar. 

60.  Mica. 

81.  Cinnabar. 

61.  Felspar. 

82.  Copper  nickel. 

62.  Albite. 

83.  Molybdenite. 

63.  Petalite. 

84.  Berthierite. 

64.  Hematite. 

85.  Bournonite. 

65.  Rutile. 

86.  Tetrahedrite. 

66.  Pyrolusite. 

87.  Onofrite,  or  Clausthalite. 

67.  Lepidolite. 

88.  Sulphides  of  arsenic  and  anti 

68.  Apatite. 

mony  (artificial). 

69.  Franklinite. 

89.  Sulphides  of  arsenic,  antimony, 

70.  Pitchblende. 

lead,  and  copper  (artificial). 

71.  Chromic  iron. 

TABLE  OF  CONTENTS. 


Preface, 

Introduction,       ....... 

List  of  substances  serving  to  illustrate  the  reactions.  . 


PACK 
V 

vii 

xiv 


FIRST  CHAPTER. 
AUXILIARY  APPARATUS  AND  REAGENTS,  . 


21—24 


SECOND  CHAPTER. 

GENERAL  ROUTINE  OF  BLOW-PIPE  ANALYSIS,         .  .        25 — 38 
Examination  in  a  closed  glass  tube,      .         .         .         .26 

Examination  in  a  glass  tube  open  at  both  ends,  .         28 
Examination  on  charcoal,  per  se,           ....     29 

Examination  in  the  platinum-pointed  pincers,    .  .         32 
Examination  with  borax  and  salt  of  phosphorus,  .         .     34 

Examination  with  carbonate  of  soda,         .         .  .         35 
Examination  with  solution  of  cobalt,    .         .  .37 

2*  B  (xvii) 


Xviii  CONTENTS. 


THIRD  CHAPTER. 

TAGE 

SPECIAL  REACTIONS  FOR  THE  DETECTION  OF  CERTAIN  SUB 
STANCES   WHEN   IN   COMBINATION   WITH   OTHERS,        .  39 — 61 
Ammonia,        ...  40 
Antimony,           ...                                                 .40 

Arsenic,          ........  41 

Bismuth,    .........  43 

Boracic  acid.  .....  43 

Bromine,    .........  44 

Cadmium,        .....  44 

Chlorine, .44 

Chromium,      ......  45 

Cobalt,        ...                   45 

Copper,  .......  40 

Fluorine,    .......  .48 

Gold, 49 

Iodine, 50 

Iron, 50 

Lead,                    51 

Lithia,    .                   52 

Manganese,          ........  53 

Mercury,          .......  53 

Nickel       .                           54 

Nitric  acid,      ........  54 

Phosphoric  acid,          .......  54 

Potassa,           ........  55 

Selenium,  .........  56 

Silica,    .                            ....  56 

Silver,        .........  57 


CONTENTS. 


XIX 


PAGE 

Sulphur, 58 

Tellurium,  .     '    .     l£ jftl   ,    •    :.-       .      .  .         .59 

Tin,        .  .  .  .         59 

Titanium,  .....         .         .         .         .     60 

Uranium,        '.  •''•/'       m         e      N  •;    •'.•'•    ^-      "*  •      ^Q 
Zinc, .61 

FOURTH  CHAPTER. 

CHARACTERISTICS  OF  THE  MOST  IMPORTANT  ORES;  THEIR  BE 
HAVIOR  BEFORE  THE  BLOW-PIPE.  AND  TO  SOLVENTS,       62 96 

Ores  of  antimony,  ......  63 

"  arsenic,          .....  64 

';  bismuth,     ......  65 

"  chromium.     .         ...         .  .67 

"  cobalt,        .         .         .         .  '      .         .  67 

"  copper,                    .69 

"  gold,  platinum,  and  iridiuni,         ...  74 

iron?                                         .-        .  .     76 

lead,  79 

'•  manganese,    ......  84 

';  mercury.    .....  .                   86 

"  nickel,  ..'.;.                  .  87 

c:  silver,         ....  89 


tin 


92 


zinc>  ...         93 

APPENDIX — Fossil  fuel,     ...  95 


FIFTH  CHAPTER. 

SYSTEMATIC  METHOD  FOR  THE  DISCRIMINATION  OF  INOR 
GANIC  COMPOUNDS,       .        .        .  97 


XX  CONTENTS. 


SIXTH  CHAPTER. 

PAGE 

ON   THE   DISCRIMINATION  OF  MINERALS  BY  MEANS  OF  THE 

BLOW-PIPE,    AIDED   BY    HUMID   ANALYSIS,    .  .       109 — 144* 

TABLES. 

TABLE  I. — BEHAVIOR  OF  THE  ALKALINE  EARTHS  AND 

THE  EARTHS  PROPER  BEFORE  THE  BLOW-PIPE,      .         146 — 149 

TABLE  II. — BEHAVIOR  OF  THE  METALLIC  OXIDES  BE 
FORE  THE  BLOW-PIPE,  .  150—163 

TABLE  III. — THE  METALLIC  OXIDES  ARRANGED  WITH 
REFERENCE  TO  THE  COLORS  WHICH  THEY  IMPART  TO 
THE  FLUXES,  .  .  .  164—169 


ABBREVIATIONS. 

OF1  for  Oxydation-flarne ;  RF1  for  Reduction-flame ;  SPh  for  Salt 
of  Phosphorus ;  Bx  for  Borax ;  Sd  for  Carbonate  of  Soda ;  SoCo  or 
SCo  for  Solution  of  Nitrate  of  Cobalt;  Ch  for  Charcoal;  Ct  for 
Coating ;  Blp  for  Blow-pipe ;  H  for  Hardness ;  G  for  Specific  Gravity. 


A    MANUAL 


OF 


BLOW-PIPE    ANALYSIS. 


FIRST   CHAPTER. 

AUXILIARY  APPARATUS  AND  REAGENTS. 

§  1.  THE  common  blow-pipe  of  gas-fitters,  jewellers,  &c.,  is  not 
very  well  adapted  for  analytical  researches,  as  the  narrow  outlet 
becomes  frequently  obstructed  by  the  moisture  which  is  exhaled 
from  the  lungs  and  condenses  in  the  tube.  To  avoid  this  incon 
venience,  the  long  cylindrical  tube  of  the  blow-pipe  should  be 
furnished  at  the  extremity  with  a  globular  or  cylindrical  chamber 
for  the  reception  of  the  condensed  water.  In  this  chamber  the  jet 
is  inserted  at  a  right  angle  to  the  tube.  Silver  is,  in  many  respects, 
the  best  material  for  the  construction  of  a  blow-pipe,  but  has  the 
disadvantage  of  becoming  very  hot  when  used  for  a  long  while,  so 
that  it  becomes  almost  impossible  to  hold  it  with  the  naked  fingers ; 
next  to  silver  stands  German  silver  and  brass.  For  jets,  platinum 
is  preferable  to  all  otjier  metals.  A  mouth-piece  of  box-wood  or 
ivory  is  convenient,  though  not  necessary. 

§  2.  Any  kind  of  flame  may  be  used  for  the  blow-pipe,  provided 
it  be  not  too  small.  Some  of  the  older  chemists  used  common 
candles  in  preference,  and  it  must  be  confessed  that,  in  the  majority 
of  cases,  the  heat  produced  by  the  flame  of  a  good  sperm  candle 
is  quite  sufficient.  Berzelius  recommended  an  oil  lamp  with  a  flat 
wick,  which  is  now  in  general  use  as  "  Berzelius's  Blow-pipe 
Lamp."  I  find  that  a  common  fluid  lamp,  with  a  rather  large 
burner,  answers  every  purpose ;  it  gives  a  very  good  heat,  and, 
besides  being  much  cleaner  than  an  oil  lamp,  admits  of  a  verv 

(21) 


22  ELDERHOX?T'S  MANUAL  OF 

quick  and  accurate  adjustment  of  the  size  of  the  flame,  by  means 
of  a  little  brass  c}rlinder,  which  is  movable,  and  slides  up  and 
down  the  burner.  The  heating  of  substances  in  glass  tubes  and 
matrasses  is  best  performed  over  a  common  spirit  lamp. 

§  3.  As  supports,  charcoal,  platinum,  and  glass  are  principally 
used.  Wood  charcoal  is  in  most  cases  the  best  support.  It  must 
be  well  burnt,  and  not  scintillate  or  smoke ;  it  must  leave  but 
little  ash  ;  charcoal  of  light  wood,  as  alder,  &c.,  has  been  found 
the  best. 

Platinum  is  used  whenever  the  reducing  action  of  the  charcoal 
acts  injuriously.  It  is  advantageously  employed  on  all  occasions 
where  no  reduction  to  the  metallic  state  takes  place,  since  the  color 
of  the  flux  is  much  better  seen  on  the  platinum  than  on  charcoal. 
It  is  mostly  used  in  the  shape  of  wire,  the  end  of  which  is  bent 
so  as  to  form  a  hook,  which  serves  as  support  to  the  flux.  As  foil, 
its  use  is  very  limited.  A  little  platinum  spoon,  of  from  about  12 
to  15  m.  m.  in  diameter,  is  very  convenient  for  fusing  substances 
with  bisulphate  of  potassa  or  nitre. 

Glass  tubes,  open  at  both  ends,  arc  used  for  calcination,  and  for 
testing  the  presence  of  substances  which  arc  volatile  at  a  high 
temperature.  The  tubes  should  be  from  5  to  8  inches  long.  Of 
glass  tubes,  scaled  at  one  end,  or  little  matrasses,  an  assortment 
should  always  be  kept  on  hand,  since  they  are  of  very  frequent  use. 

§  4.  Of  other  apparatus,  the  most  necessary  are : 

A  mortar  of  agate  or  chalcedony,  from  1 J  to  2  inches  in  width, 
with  pestle  of  the  same  material. 

A  forceps  of  brass  or  German  silver,  with  platinum  points. 

A  forceps  of  steel. 

A  little  hammer  and  anvil,  both  of  steel  and  well  polished. 

A  three-cornered  file  for  cutting  glass  tubes,  trying  the  hardness 
of  minerals,  &c. 

A  little  magnet. 

A  pocket  magnifying  glass. 

A  set  of  watch  glasses,  which  are  very  convenient  for  the  recep 
tion  of  the  assay-piece,  the  metallic  globules,  &c. 

§  5.  Of  reagents,  Carbonate  of  Soda,  Borax,  and  Salt  of  Phos 
phorus,  are  the  most  important  ones  ;  but  there  are  others,  which, 


BLOW-PIPE    ANALYSIS.  23 

though  not  so  extensively  used,  still  are  indispensable  for  the 
detection  of  certain  substances  ;  those  only  shall  here  be  men 
tioned  ;  others,  the  use  of  which  is  very  limited,  are  omitted  in 
this  list. 

Carbonate  of  Soda:  The  monocarbonate  or  the  bicarbonate  may 
be  indifferently  employed ;  it  must  be  perfectly  free  from  sulphuric 
acid,  for  the  presence  of  which  it  may  be  tested  as  shown  §  107. 
The  neutral  oxalate  of  potassa  and  the  commercial  [fused]  cyanide 
of  potassium  deserve  in  many  cases  the  preference,  their  reducing 
powers  being  superior  to  that  of  carbonate  of  soda. 

Borax:  The  commercial  article  is  purified  by  crystallization,  the 
crystals  dried  and  reduced  to  a  coarse  powder. 

Salt  of  Phosphorus:  [double  phosphate  of  soda  and  ammonia] 
100  parts  of  crystallized  common  phosphate  of  soda  and  16  parts 
of  sal  ammoniac  are  dissolved  in  32  parts  of  water;  the  solution  is 
aided  by  heat,  the  liquid  filtered  while  hot,  and  the  crystals,  which 
form  on  cooling,  dried  between  blotting  paper.  When  pure  it  gives 
a  glass  which,  on  cooling,  remains  transparent;  if  this  is  not  the 
case  it  must  be  purified  by  recrystallization.  It  is  kept  as  a  coarse 
powder. 

Bisulphate  of  Potassa:  It  is  employed  in  the  fused  [anhydrous] 
state  as  a  coarse  powder;  it  must  be  kept  in  a  bottle  provided  with 
a  ground  glass  stopper. 

Vitrified  Boracic  Acid:  Is  employed  in  the  state  of  a  coarse 
powder. 

Fluor-spar :  Must  be  deprived  of  water  by  ignition ;  must  be  per 
fectly  free  from  boracic  acid,  which  may  be  tested  as  described  §  61. 
It  is  convenient,  to  keep  in  a  separate  bottle  a  mixture  of  1  part  of 
finely  powdered  fluor-spar  with  4^  parts  of  bisulphate  of  potassa. 

Nitrate  of  Cobalt,  in  solution:  It  must  be  pure,  free  from  alkali, 
and  [for  many  purposes]  free  from  nickel;  it  is  kept  in  a  bottle  with 
a  ground  glass  stopper,  which,  very  conveniently,  is  so  much  elon 
gated  as  to  dip  into  the  liquid.  Instead  of  the  nitrate,  the  oxalate 
of  cobalt  may  be  used,  which,  being  in  the  shape  of  powder,  is 
advantageously  substituted  for  the  former  in  travelling. 

Nitrate  or  Oxalate  of  Nickel:  It  must  be  perfectly  free  from 
cobalt;  it  is  tested  with  borax,  with  which  it  ought  to  produce  a 
pure  brown  glass. 


24  ELDERHORST'S  MANUAL  OF. 

Oxide  of  Copper:  It  is  best  prepared  by  heating  the  nitrate  to 
ignition. 

Chloride  olf  Silver:  It  is  prepared  by  precipitating  a  solution  of 
nitrate  of  silver  with  hydrochloric  acid,  washing  the  precipitate, 
and  making  it  into  a  thick  paste  with  water,  which  is  kept  in  a  small 
glass-stoppered  bottle.  This  reagent  should  not  be  used  with  pla 
tina  wire,  since  the  silver  fuses  with  the  platina  to  an  alloy;  thin 
iron  wire  is  in  this  case  substituted  for  the  platina.  For  each 
experiment  a  fresh  hook  should  be  made. 

Pure  Metallic  Lead:  It  is  easily  obtained  pure  by  decomposing 
a  solution  of  the  acetate  by  metallic  zinc;  the  precipitate  is  repeat 
edly  washed  with  water  and  then  dried  between  blotting  paper. 

Metallic  Iron:  In  the  shape  of  thin  wire  [harpsichord  wire]. 

Metallic  Tin:  Usually  in  the  shape  of  foil,  which  is  cut  into  strips 
and  rolled  up  tightly. 

Bone-ash :  In  the  state  of  very  fine  powder. 

Test  Paper:  Blue  and  red  Litmus  Paper,  and  Brazil  Wood 
Paper. 

§  6.  If  the  analytical  research  is  strictly  confined  to  blow-pipe 
operations,  the  above  enumerated  reagents  are  sufficient;  but  if,  a« 
is  sometimes  advantageously  done,  some  simple  operations  of  the 
humid  method  of  chemical  analysis  arc  called  to  aid,  the  list  must 
be  somewhat  extended.  The  most  important  of  these  reagents,  all 
of  which  must  be  kept  in  bottles  with  ground  glass  stoppers,  are : 
Sulphuric  Acid,  Hydrochloric  Acid,  Nitric  Acid,  Oxalic  Acid,  Hy 
drate  of  Potassa,  Ammonia,  Carbonate  of  Ammonia,  Chloride  of 
Ammonium,  Molybdate  of  Ammonia,  Ferrocyanide  of  Potassium, 
Ferridcyanide  of  Potassium,  Bichloride  of  Platinum,  Acetate  of 
Lead,  Sulphuretted  Hydrogen  Water,  Sulphydrate  of  Ammonia. 
Alcohol,  Distilled  Water. 

The  principal  auxiliary  apparatus  are:  Test-tubes  and  Test-tube 
Hack,  small  Porcelain  Dishes,  small  Beaker  Glasses,  some  Glass 
Funnels  and  Filtering  Stand,  Filtering  Paper,  Platinum  Crucible, 
some  Glass  Rods  and  round  Glass  Plates,  for  covering  beaker 
glasses,  a  common  Spirit  Lamp,  and  a  Spirit  Lamp  with  Argand 
Burner. 


BLOW-PIPE  ANALYSIS.  25 


SECOND  CHAPTER. 

GENERAL  ROUTINE  OF   BLOW-PIPE   ANALYSIS. 

§  7.  On  examining  a  substance  before  the  blow-pipe,  with  a  view 
to  determine  its  nature  or  to  ascertain  the  presence  or  absence  of 
certain  matter,  it  is  advisable  to  follow  a  systematic  way,  composed 
of  a  series  of  operations,  and  to  attentively  observe  the  changes 
which  the  body  undergoes  under  the  influence  of  the  various  agents 
which  are  brought  to  act  upon  it.  The  various  operations  which 
the  assay  is  submitted  to  are  so  many  questions,  to  which  the 
phenomena  which  we  observe  constitute  so  many  answers;  and 
from  their  appearance  or  non-appearance,  we  are  able  to  draw 
definite  conclusions  as  to  the  nature  of  the  substance  under  ex- 
«im  ination.  . 

The  following  order,  and  the  rules  to  be  observed  in  the  execution 
of  the  various  operations  are,  essentially,  the  same  as  first  pointed 
out  and  laid  down  by  Berzelius. 

1.  Examination  in  a  glass  tube,  sealed  at  one  end,  or  a  matrass 

-2.  Examination  in  a  glass  tube  open  at  both  ends. 

3.  Examination  on  charcoal  per  se. 

4.  Examination  in  the  platinum-pointed  pincers,  or  on  platinum 
wire  per  se. 

5.  Examination  with  borax,  and  salt  of  phosphorus. 

6.  Examination  with  carbonate  of  soda. 

7.  Examination  with  solution  of  cobalt. 

Regarding  the  size  of  the  assay,  a  piece  the  size  of  a  mustard 
scod  will  generally  be  found  sufficient;  larger  pieces,  without  show 
ing  the  reaction  more  distinctly,  requiring  so  much  more  labor.  In 
some  cases,  however,  it  is  advantageous  to  employ  a  greater  quan- 
tity,  ex.  gr.  in  reductions,  or  in  heating  in  a  glass  tube;  for  the 
larger  the  metallic  globule,  and  the  greater  the  amount  of  the  sub 
limate  produced,  the  more  readily  can  its  nature  be  ascertained. 
3 


26  ELDERHORST'S  MANUAL  OF 

Examination  in  a  closed  Glass  Tube,  or  a  Matrass. 

§  8.  The  assay-piece  is  introduced  into  a  glass  tube,  sealed  at 
one  end,  or  into  a  small  matrass,  and  heat  applied  by  means  of  a 
common  spirit  lamp.  The  heat  must  at  first  be  very  low,  but  may 
be  gradually  raised  to  redness,  if  necessary.  By  this  treatment  we 
learn : 

§  9.    1.  Whether  the  substance  is  entirely  or  partly  volatile  or  not. 

Among  the  phenomena  to  be  observed,  the  following  are  deserving 
of  particular  attention: 

The  substance  gives  out  water,  which  partly  escapes  and  partly 
condenses  in  the  colder  portion  of  the  tube.  This  points  to  the 
presence  of  a  salt  containing  water  of  crystallization  [No.  22],  or 
to  the  presence  of  a-.hydrate,  or  to  such  salts  which  contain  water 
mechanically  inclosed  between  the  Iamina3  of  the  crystals  [No.  18]; 
in  this  case  the  body  usually  decrepitates.  The  drops  of  condensed 
water  are  to  be  examined  with  test-paper:  an  alkaline  reaction  de 
notes  the  presence  of  ammonia,  an  acid  reaction  the  presence  of 
some  volatile  acid,  as  sulphuric,  nitric,  hydrochloric,  hydrofluoric 
acid,  &c. 

§10.  The  substance  gives  out  a  gas  or  vapor.  Those  of  most 
usual  occurrence  arc: 

a.  Oxygen,  easily  recognized  by  rekindling  into  flame  a  match 
which  has  been  extinguished,  so  as  to  leave  only  a  spark  at  the 
extremity;  points  to  the  presence  of  a  peroxide,  nitrate,  chlorate, 
brouiate  or  iodate  [No.  20]. 

b.  Sulphurous  acid,  easily  recognized  by  its  peculiar  odor  and 
action  on  blue  litmus  paper;  indicates  the  presence  of  a  sulphate  or 
sulphite^No.  22]. 

c.  Sulphuretted  hydrogen,  recognized  by  its  peculiar  odor;  indi-^ 
cates  the  presence  of  sulphides  containing  water. 

d.  Nitrous  acid  or  peroxide  of  nitrogen,  recognized  by  its  deep 
orange  red  color  and  acid  reaction;   indicates  the  presence  of  a 
nitrite  or  nitrate  [No.  23]. 

e.  Carbonic  acid,  recognized  by  causing  a  turbidity  in  a  drop  of 
lime-water   suspended  from  a  watch-crystal   and  exposed  to  the 
escaping  gas;  points  to  the  presence  of  a  carbonate. 


BLOW-PIPE    ANALYSIS.  2Y 

/.  Cyanogen,  recognized  by  its  peculiar  odor  and  by  burning  with 
a  crimson  flame ;  indicates  the  presence  of  a  cyanogen-compound. 

g.  Ammonia,  recognized  by  its  odor  and  alkaline  reaction ;  indi 
cates  the  presence  of  an  ammoniacal  salt  or  of  an  organic  nitro 
genous  substance;  in  the  latter  case,  the  mass  usually  blackens, 
and  evolves  at  the  same  time  either  cyanogen  or  empyreumatic  oils 
of  offensive  odor  [No.  3]. 

§  11.  The  substance  yields  a  sublimate.  The  sublimate  is  either 
white  or  possessed  of  a  peculiar  color.  White  sublimates  are 
formed  by 

a.  Many  salts  of  ammonia;  on  removing  the  sublimate  from  the 
tube,  placing  it  on  a  watch-crystal,  adding  a  drop  of  hydrate  of 
potassa,  and  applying  heat,  ammonia  is  evolved  [Xo.  19]. 

b.  The  chlorides  of  mercury;  the  subchloride  sublimes  without 
previous  fusion;  the  protochloride  fuses  first,  then  sublimes;  the 
sublimate  is  yellow  while  hot,  but  becomes  white  on  cooling  [Nos. 
39  and  40]. 

c.  Oxide  of  antimony;  it  fuses  first  to  a  yellow  liquid,  then  sub 
limes;   the  sublimate  consists  of  lustrous  needle-shaped  crystals 
[No.  24]. 

d.  Arsenous  acid;  the  sublimate  consists  of  octahedral  crystals 
[Xo.  25]. 

e.  Tellurous  acid;  shows  a  reaction  similar  to  that  of  oxide  of 
antimony,  but  requires  a  much  higher  temperature;  the  sublimate 
is  amorphous. 

Sublimates  possessed  of  metallic  lustre,  so-called  metallic  mir 
rors,  are  formed  by: 

a.  Metallic  arsenic  and  arsenides  containing  more'  than  one 
equivalent  of  arsenic  to  two  of  metal,  also,  some  sulph-arsenides 
[No.  77];  cutting  the  tube  below  the  sublimate,  and  exposing  the 
mirror  to  gentle  heat  in  the  flame  of  a  spirit  lamp,  the  peculiar  odor 
of  arsenic  is  perceived. 

b  V ercury,  amalgams,  and  some  salts  of  mercury;  the  sublimate 
consists  of  minute  globules  of  metallic  mercury,  which,  by  friction 
with  a  piece  of  copper  wire,  readily  unite  to  larger  globules  [Xo.  47]. 

c.  Some  alloys  of  cadmium. 

d.  Tellurium;  only  at  a  very  high  temperature;  the  sublimate 
consists  of  small  globules,  which  solidify  on  cooling. 


28  ELDERIIORST'S  MANUAL  OF 

Sublimates  possessed  of  distinct  color  are  formed  by: 

a.  Sulphur  and  sulphides  containing  a  large  amount  of  sulphur ; 
the  sublimate  is  from  deep-yellow  to  brownish-red  while  hot,  but 
pure  sulphur-yellow  when  cold  [No.  75]. 

b.  The  sulphides  of  antimony,  alone  or  in  combination  with  other 
sulphides;  the  sublimate  forms  only  at  a  very  high  temperature, 
and  is  deposited  at  a  short  distance  from  the  assay-piece;   it  is 
black  while  hot,  reddish-brown  when  cold  [No.  74]. 

c.  The  sulphides  of  arsenic  and  some  compounds  of  metallic  sul 
phides  with -arsenides;  the  sublimate  is  dark  brownish-red  while 
hot,  but  from  reddish-yellow  to  red  when  cold  [No.  80]. 

d.  Cinnabar;  the  sublimate  is  black,  without  lustre,  and  yields 
a  red  powder  on  being  scratched  with  a  knife  [No.  81]. 

e.  Selenium  and  some  selcnides;  the  sublimate  appears  only  at 
a  high  temperature,  is  of  a  reddish  or  black  color,  and  yields  a  dark- 
red  powder;   at  the  open  end  of  the  tube  the  peculiar  odor  of 
selenium  (resembling  rotten  horse-radish)  is  perceived  [No.  81]. 

§  12.  2.  Whether  the  substance  undergoes  any  change,  or  re 
mains  unaltered. 

Many  substances,  under  this  treatment,  suffer  physical  changes 
without  being  affected  in  their  chemical  constitution.  A  great 
many  minerals,  when  heated,  decrepitate;  others  phosphoresce,  as 
fluor-spar  and  apatite.  The  most  important  of  these  physical 
changes,  is  that  of  color:  from  white  to  yellow,  and  white  again 
on  cooling,  points  to  oxide  of  zinc  [No.  36] ;  from  white  to  yellowish- 
brown,  dirty  pale-yellow  on  cooling,  points  to  oxide  of  tin  [No.  33] ; 
from  white  to  brownish-red,  yellow  when  cold,  and  fusible  at  a  red 
heat,  points*  to  oxide  of  lead  [No.  72];  from  white  to  orange-yellow 
or  reddish-brown,  pale  yellow  when  cold,  and  fusible  at  a  bright 
red  heat,  points  to  teroxide  of  bismuth ;  from  red  to  black,  and  red 
again  on  cooling,  points  to  sesquioxide  of  iron  [No.  64], 

Examination  in  a  Glass  Tube  open  at  both  ends. 

§  13.  The  assay-piece  is  introduced  into  the  tube  to  a  depth  of 
about  half  an  inch,  the  end  to  which  it  lies  nearest  slightly  inclined, 
and  heat  applied.  The  air  contained  in  the  tube  becomes  heated  ; 


BLOW-PIPE   ANALYSIS.  29 

it  rises,  escapes  from  the  upper  end,  and  fresh  air  enters  from  be 
low.  In  this  manner  a  calcination  is  effected,  and  many  substances 
which  remained  unchanged  when  heated  in  a  matrass,  yield  subli 
mates  or  gaseous  products  when  subjected  to  this  treatment,  owing 
to  the  formation  of  volatile  oxides. 

By  this  means  we  can  easily  detect  the  presence  of  the  following 
substances : 

§  14.  Sulphur  ;  sulphurous  acid  is  formed,  which  is  characterized 
by  its  peculiar  odor  and  action  on  moistened  litmus  paper  [No.  75]. 

§  15.  Arsenic  ;  if  present  in  sufficient  quantity  it  yields  a  white 
and  very  volatile  sublimate  of  arsenous  acid,  consisting  of  minute 
octahedral  crystals  ;  by  application  of  gentle  heat  it  may  be  driven 
from  one  place  to  another  [No.  77]. 

§  16.  Antimony  ;  white  fumes  of  antimonious  acid  are  given  out 
which  partly  escape,  and  partly  condense  in  the  upper  part  of  the 
tube.  The  sublimate  is  a  white  powder,  and  may,  if  consisting  of 
pure  antimonious  acid,  be  volatilized  by  heat.  In  most  cases,  however, 
the  oxidation  proceeds  farther,  and  the  antimonate  of  the  oxide  of 
antimony,  a  non-volatile  white  powder,  is  formed  [No.  41]. 

§  It.  Metallic  Bismuth  ;  it  is  converted  into  oxide,  which  con 
denses  at  a  short  distance  from  the  assay,  and  which,  by  heat,  may 
be  fused  to  brownish  globules  [No.  43]. 

Mercury  and  amalgams  ;  yield  sublimates  of  metallic  mercurv 
[No.  47]. 

§  18.  Tellurium  and  tellurides  ;  tellurous  acid  is  produced,  which 
condenses  in  the  upper  part  of  the  tube  to  a  white  non-volatile  pow 
der  ;  on  application  of  heat  it  fuses  to  colorless  globules. 

Selenium  and  selenides ;  evolve  a  gaseous  oxide  of  a  peculiar 
odor,  resembling  that  of  rotten  horse-radish  [No.  87]. 

Examination  on  Charcoal  per  se. 

§  19.  In  examinations  of  this  kind,  particular  attention  must  be 
paid  to  the  odor  of  the  escaping  gases,  and  to  the  color  and  other 
properties  of  the  rings,  or  coatings,  which  form  on  the  charcoal 
around  the  assay-piece.  The  interior  [reduction  flame,  II  Fl]  and 
exterior  [oxidation  flame,  0  Fl]  cones  of  the  flame  acting  in  an  op 
posite  sense,  the  phenomena  produced  wrill  be  very  different ;  hence' 
3* 


30  ELDERHORST'S  MANUAL  OF 

two  assays  should  always  be  made,  exposing  the  substance  first  to 
the  action  of  the  0  Fl  and  then  to  the  action  of  the  R  Fl.  The  fol 
lowing  bodies  undergo,  when  submitted  to  this  treatment,  charac 
teristic  changes. 

§  20.  Arsenic:  It  is  volatilized  without  previous  fusion,  the  Ch 
is  covered  with  a  white  Ct,  which  is  far  distant  from  the  assay- 
piece,  and  which  is  produced  by  both  the  0  Fl  and  R  Fl ;  the  Ct 
is  very  volatile,  and  is  easily  driven  away  by  the  Blp  flame,  emit 
ting  the  peculiar  alliaceous  odor  characteristic  of  arsenic  [No.  42]. 

§  21.  Antimony :  It  enters  readily  into  fusion  and  covers  the  Ch 
with  white  oxide  ;  the  ring  is  not  so  far  distant  from  the  assay- 
piece  as  in  the  case  of  arsenic  ;  it  may  be  driven  away  by  the  Blp 
flame,  but  is  not  so  volatile  as  that  of  arsenic,  and  does  not  emit 
an  alliaceous  odor.  Metallic  antimony,  when  fused  on  Ch  and 
heated  to  redness,  remains  a  considerable  time  in  a  state  of  ignition 
without  the  aid  of  the  Blp,  disengaging,  at  the  same  time,  a  thick 
white  smoke,  which  is  partly  deposited  on  the  Ch  around  the  me 
tallic  globule  in  white  crystals  of  a  pearly  lustre  [No.  41]. 

§  22.  Bismuth  :  It  fuses  readily  in  both  flames  and  covers  the  Ch 
with  oxide,  which  is  dark  orange-yellow  while  hot  and  lemon- 
yellow  when  cold.  The  yellow  Ct  is  usually  surrounded  by  a  white 
ring,  consisting  of  carbonate  of  bismuth.  The  Ct  is  somewhat 
nearer  the  assay  than. that  of  antimony  ;  it  may  be  driven  away  by 
both  flames  ;  but  the  oxide  of  antimony,  when  played  upon  with  the 
R  Fl,  imparts  to  the  flame  a  greenish-blue  tinge,  which  the  oxide 
of  bismuth  does  not  [No.  43]. 

§  23.  Lead  :  It  fuses  easily  and  coats  the  Ch  in  both  flames 
with  oxide,  which  is  dark  lemon-yellow  while  hot  and  sulphur- 
yellow  when  cold  ;  in  thin  layers  it  is  bluish-white  and  consists  of 
carbonate.  The  Ct  is  found  at  the  same  distance  from  the  assay 
as  that  of  bismuth  ;  it  may  be  driven  away  by  both  flames  ;  when 
played  upon  with  the  R  Fl  it  imparts  to  the  flame  an  azure-blue 
color  [No.  11]. 

§  24.  Cadmium :  It  fuses  readily  ;  exposed  to  the  0  Fl  it  burns 
with  a  dark-yellow  flame,  emitting  brown  fumes  of  oxide  which 
cover  the  Ch  around  the  assay.  This  Ct  is  very  characteristic ;  it 
is,  when  cold,  of  a  reddish-brown  color,  in  thin  layers  orange-yellow ; 


BLOW-PIPE  ANALYSIS.  31 

it  is  easily  volatilized  by  both  flames,  without  imparting  a  color  to 
them  [No.  44]. 

§  25.  Zinc  :  It  fuses  readily  ;  exposed  to  the  0  Fl  it  burns  with 
an  intensely  luminous  greenish-white  flame,  emitting  at  the  same 
time  a  thick  white  smoke  which,  partly  condensing  on  the  Ch, 
covers  it  with  oxide,  yellow  while  hot  and  white  when  cold.  The 
Ct  when  played  upon  with  the  0  Fl  becomes  luminous,  but  does 
not  disappear  [No.  46]. 

§  26.  Tin :  It  fuses  readily ;  exposed  to  the  O  Fl  it  is  converted 
into  oxide,  which  may  be  blowrn  away  and  thus  be  made  to  appear 
as  a  Ct ;  it  is  always  found  closely  surrounding  the  assay-piece,  is 
slightly  yellow  and  luminous  wrhile  hot,  white  when  cold,  and  non 
volatile  in  both  flames.  Exposed  to  the  R  Fl  the  molten  metal 
retains  its  bright  metallic  aspect  [No.  13]. 

§  27.  Silver  :  When  exposed  for  a  long  time  to  the  action  of  the 
R  Fl  it  yields  a  slight  dark-red  Ct  of  oxide  [No.  45]. 

§  28.  Selenium :  It  fuses  very  readily  in  both  flames  with  disengage 
ment  of  brown  fumes  ;  at  a  short  distance  from  the  assay  a  steel- 
gray  Ct  of  a  feeble  metallic  lustre  is  deposited  ;  played  upon  with 
the  R  Fl  it  disappears  wTith  emission  of  a  strong  odor  of  rotten 
horse-radish,  at  the  same  time  imparting  to  the  flame  a  fine  blue 
color  [No.  87]. 

§  29.  Tellurium :  It  fuses  very  readily  and  coats  the  Ch  in  both 
flames  with  tellurous  acid  ;  the  Ct  is  not  very  far  distant  from  the 
assay  ;  it  is  of  a  white  color  with  a  red  or  dark^ellow  edge  ;  played 
upon  with  the  R  Fl  it  disappears,  imparting  to  the  flame  a  green 
tinge. 

§  30.  Besides  the  above  named  metals  there  are  some  other  sub 
stances  which,  when  treated  before  the  Blp  upon  Ch  cover  it  with 
coatings,  which  may  be  driven  away  when  played  upon  with  the 
O  Fl,  and  which  show  in  many  cases  a  great  resemblance  to  the 
Ct  produced  by  antimony.  Among  the  bodies  possessing  this 
property  the  following  are  the  most  frequently  occurring  ones : 

The  sulphurides  of  potassium,  sodium,  and  lithium. 

The  chlorides  of  ammonium,  potassium,  sodium,  and  lithium. 

The  chlorides  of  mercury,  antimony,  zinc,  cadmium,  lead,  bis 
muth,  tin,  and  copper. 


32  ELDERHORST'S  MANUAL  OP 

The  bromides  and  iodides  of  potassium  and  sodium. 

Examination  in  the  Platinum-pointed  Pincers. 

§  31.  This  experiment  serves  a  double  purpose.  It  acquaints  us 
with  the  degree  of  fusibility  of  the  assay,  and  shows  the  presence 
or  absence  of  such  substances  which  possess  the  property  of  impart 
ing  to  the  flame  a  peculiar  color.  Many  metals,  the  sulphurides, 
and  some  other  compounds  act  upon  metallic  platinum  at  a  high 
temperature ;  the  fusibility,  &c.,  of  such  substances  ought  to  be 
tested  on  Ch.  Others,  again,  fuse  so  easily  that  they  cannot  be 
held  a  sufficiently  long  time  between  the  pincers  to  observe  the 
color  which  they  impart  to  the  flame  ;  they  are  most  conveniently 
attached  to  the  hook  of  the  platinum  wire,  which  is  best  done  by 
heating  the  wire  to  redness  and  then  touching  the  powder  of  the 
assay  with  it ;  a  sufficient  quantity  generally  remains  adhering  to 
the  wire. 

Some  minerals  decrepitate  violently  as  soon  as  they  are  touched 
with  the  flame  ;  in  such  cases,  Berzelius  advises  to  powder  the  sub 
stance  very  finely  in  an  agate-mortar  with  addition  of  a  little  water, 
to  place  one  or  two  drops  of  the  mixture  on  a  piece  of  Ch,  and  to 
gently  heat  it  by  means  of  the  Blp  flame  until  the  mass  lies  loosely 
upon  the  Ch  ;  it  may  then  be  taken  up  and  held  by  the  pincers. 
The  same  process  is  advantageously  employed  with  substances  which 
fuse  only  at  a  very  high  temperature.  In  all  other  cases  the  sub 
stance  is  roughly  powdered  and  a  thin  piece  which  shows  promi 
nent  edges  selected  for  the  experiment. 

The  assay  is  exposed  to  the  action  of  the  inner  cone  of  the  flame. 
when  the  outer  cone  may  exhibit  the  following  changes  of  color : 

§  32.  1.  Yellow. 

Soda  and  its  salts  cause  an  enlargement  of  the  outer  flame,  and 
impart,  at  the  same  time,  an  intense  reddish-yellow  color  [No.  18]. 
The  presence  of  other  substances  which  also  possess  the  property 
of  coloring  the  flame,  but  not  in  so  high  a  degree,  does  not  prevent 
the  reaction.  Silicates  containing  soda,  exhibit  the  same  phenome 
non  to  a  smaller  or  greater  extent,  according  to  their  degree  of 
fusibility  and  the  amount  of  soda  which  they  contain  [No.  62]. 
With  many  salts  of  soda,  which  do  not  exhibit  the  reaction  very 


BLOW-PIPE    ANALYSIS.  33 

distinct!}',  it  can  be  produced  by  mixing  the  salt  with  some  chloride 
of  silver  to  a  paste  (v.  §  5),  fastening  it  to  the  hook  of  a  thin  iron- 
wire,  and  then  exposing  it  to  the  action  of  the  inner  flame. 

§  33.  2.  Violet. 

Potassa  and  many  of  its  salts  impart  to  the  outer  flame  a  distinct 
violet  color  [Xo.  15].  The  presence  of  a  small  quantity  of  a  salt 
of  soda  or  lithia  prevents  the  reaction.  An  addition  of  chloride 
of  silver  favors  the  reaction  with  the  carbonate,  nitrate,  and  some 
other  salts  of  potassa. 

§  34.  3.  Red. 

Lithia  and  its  salts  impart  to  the  outer  flame  a  fine  carmine-red 
color  [Xo.  63]  ;  the  chloride  of  lithium  shows  the  reaction  better 
than  any  other  salt.  The  presence  of  a  salt  of  potassa  does  not 
prevent  the  reaction ;  the  presence  of  even  a  small  quantity  of  a 
salt  of  soda  changes  the  color  to  yellowish-red.  An  addition  of 
cllloride  of  silver  favors  the  reaction  with  many  salts  of  lithia. 

Chloride  of  strontium  and  some  other  salts  of  strontia,  ex.  gr.. 
the  carbonate  and  the  sulphate,  color  the  outer  flame,  immediately 
or  after  a  while,  carmine-red  [Xo.  57].  The  presence  of  baryta 
prevents  the  reaction.  The  carbonate  and  sulphate  of  strontia 
show  the  reaction  remarkably  well  when  mixed  with  chloride  of 
silver  and  heated  on  iron-wire  (v.  §  5). 

Chloride  of  calcium,  calcareous  spar,  many  compact  limestones, . 
and  fluor-spar,  color  the  outer  flame,  immediately  or  after  a  while, 
red  ;  the   color  is  not  so  intense  as  that  produced  by  strontia. . 
Gypsum  and  anhydrite  impart  at  first  a  pale  yellow,  afterwards  a 
red  color  of  little  intensity  [Xo.  56].     An  addition  of  chloride  of 
silver  usually  increases  the  intensity  of  the  color. 

§  35.  4.  Green. 

Chloride  of  barium,  carbonate  and  sulphate  of  baryta,  color  the 
outer  flame  yellowish-green.  The  presence  of  lime  does  not  pre 
vent  the  .reaction  [Xo.  58].  An  addition  of  chloride  of  silver 
makes  the  color  much  more  intense. 

Oxide  of  copper  and  some  of  its  salts,  ex.  gr.  the  carbonate, 
sulphate,  and  nitrate,  impart  to  the   outer  flame  a  fine  emerald- 
green  color.    Iodide  of  copper  and  some  silicates  containing  copper, 
ex.  gr.  dioptase  and  chrysocolla,  act  in  the  same  manner  [Xo.  73] 
C 


34  ELDERHORST'S  MANUAL  or 

An  addition  of  chloride  of  silver  produces  increased  intensity 
of  color. 

Phosphoric  acid,  phosphates,  and  minerals  containing  phosphoric 
acid,  impart  to  the  outer  flame  a  bluish-green  color  [No.  3]. 

Boracic  acid  colors  the  "outer  flame  yellowish-green  (greenfinch 
color)  [No.  5] ;  if  a  small  quantity  of  soda  is  present  the  color  is 
mixed  with  yellow. 

Molybdic  acid,  oxide  of  molybdenum,  and  the  native  sulphide 
of  molybdenum,  color  the  outer  flame  yellowish-green,  like  baryta 
[No.  83]. 

Tellurous  acid  enters  into  fusion,  emits  white  fumes,  and  colors 
the  outer  flame  green. 

§  3G.  5.  Blue. 

Arsenic  and  some  arsenides,  ex.  gr.  smaltinc  and  copper-nickel 
[No.  82]  when  heated  on  Ch  impart  a  light-blue  color  to  the  outer 
ilame.  Some  arsenates,  ex.  gr.  scorodite  and  cobalt  bloom,  exhibit 
the  same  phenomenon  in  the  pincers. 

Antimony,  fused  on  Ch  in  R  Fl  is  surrounded  by  a  very  feeble 
bluish  light  [No.  41]. 

Metallic  lead,  fused  on  Ch  in  R  Fl  is  surrounded  by  an  azure- 
blue  light.  Many  salts  of  lead,  heated  in  the  pincers  or  on  platinum 
wire,  impart  an  intense  azure-blue  color  to  the  outer  flame  [No.  11]. 

Chloride  of  copper  colors  the  outer  flame  intensely  azure-blue ; 
after  a  while  the  color  becomes  green,  owing  to  the  formation  of 
oxide  of  copper  [No.  37]. 

Bromide  of  copper  colors  the  outer  flame  greenish-blue ;  after  a 
while  the  cojor  changes  to  green. 

Selenium,  fused  on  Ch  in  R  Fl  vaporizes  with  an  azure-blue  light. 

Examination  with  Borax  and  Salt  of  Phosphorus. 

§  37.  The  examination  of  the  assay  with  borax  and  salt  of  phos 
phorus  is  eminently  adapted  to  detect  the  presence  of  metallic 
oxides,  a  great  number  of  them  possessing  the  property  of  being 
at  a  high  temperature  dissolved  by  these  fluxes  with  a  peculiar 
color.  Unoxidizcd  metals  and  metallic  sulphides,  arsenides,  &c., 
differ  in  this  respect  very  materially  from  the  pure  oxides;  hence 


BLOW-PIPE    ANALYSIS.  35 

it  is  necessary,  before  performing  the  experiment,  to  convert  all 
such  substances  into  oxides.  This  is  effected  by  calcination,  on 
Ch  or  in  an  open  glass  tube.  The  finely  powdered  assay  is  placed 
on  Ch  and  alternately  treated  with  the  0  Fl  and  R  Fl,  and  this 
process  is  repeated  until  the  substance  no  longer  emits,  while  in 
the  incandescent  state,  the  odor  of  sulphur  or  arsenic.  The  heat 
must  never  be  raised  so  high  as  to  cause  fusion,  and  between  every 
two  succeeding  calcinations  the  assay  should  be  taken  from  the  Ch 
and  freshly  powdered. 

The  experiment  is  generally  made  on  platinum  wire,  where  the 
color  of  the  bead  is  more  readily  observed ;  Ch  is  used  only  in  such 
cases  where  the  substance  under  examination  contains  metallic 
oxides  which  are  easily  reduced.  It  is  not  sufficient  to  observe 
the  color  of  the  bead  after  cooling ;  but  all  changes  of  color  which 
take  place  during  the  action  of  the  flame,  and  through  all  the 
various  stages  of  cooling,  should  be  carefully  noticed. 

Some  substances  possess  the  property  of  forming  a  limpid  glass 
with  borax,  which  preserves  its  transparency  on  cooling,  but  which, 
if  slightly  heated  in  the  0  Fl,  becomes  opaque,  when  the  flame 
strikes  it  in  an  unequal  or  intermittent  manner.  This  operation 
has  received  the  name  of  "  flaming,"  and  any  substance  thus  acted 
upon  is  said  to  become  "  opaque  by  flaming." 

The  third  and  fourth  columns  of  Tables  I  and  II  exhibit  the 
behavior  of  the  most  important  oxides  to  borax  and  salt  of  phos 
phorus. 

In  Table  III  the  oxides  are  arranged  with  reference  to  the  color 
which  they  impart  to  the  beads  in  0  Fl  and  R  Fl. 

Examination  with  Carbonate  of  Soda. 

§  38.  In  subjecting  a  body  to  the  treatment  of  Sd  we  have  to 
direct  our  attention  to  two  points. 

Some  substances  unite  with  Sd  to  fusible  compounds,  others  form 
infusible  compounds,  and  others  again  are  not  acted  upon  at  all ; 
in  the  last  case  the  Sd  is  absorbed  by  the  Ch  and  the  assay  is  left 
unchanged.  With  Sd  unite  to  fusible  compounds  with  effervescence : 

§  39.  Silicic  acid ;  it  fuses  to  a  transparent  glassy  bead  which, 


36  ELDERHORST'S  MANUAL  OF 

after  cooling,  remains  transparent  if  the  Sd  has  not  been  added 
in  excess  [No.  54]. 

Titanic  acid ;  it  fuses  to  a  transparent  glassy  bead  which,  when 
cold,  is  opaque  and  of  crystalline  structure  [No.  65]. 

Tungstic  and  molybdic  acids  ;  the  mass,  after  the  union  has  been 
effected,  is  absorbed  by  the  Ch  [No.  31  and  No.  34]. 

The  salts  of  baryta  and  strontia  form  with  Sd  fusible  compounds 
which  are  absorbed  by  the  Ch  [No.  5t  and  No.  58]. 

§  40.  The  second  point  to  be  observed  is  the  elimination  of 
metallic  matter.  Of  tne- metallic  oxides,  when  treated  with  Sd  on 
Ch  in  R  Fl,  are  reduced :  the  oxides  of  the  noble  metals  and  the 
oxides  of  arsenic,  antimony,  bismuth,  cadmium,  copper,  cobalt,  iron, 
lead,  mercury,  nickel,  tin,  zinc,  molybdenum,  tungsten,  and  tellurium. 
Of  these,  arsenic  and  mercury  vaporize  so  rapidly  that  frequently 
not  even  a  coating  is  left  on  the  Ch.  Antimony,  bismuth,  cadmium, 
lead,  zinc,  and  tellurium  are  partly  volatilized  and  form  distinct 
coatings  on  the  Ch.  The  non-volatile  reduced  metals  are  found 
mixed  up  with  the  Sd.  To  separate  them  from  the  adhering  Sd 
and  Ch  powder,  we  may  proceed  in  the  following  manner : 

The  fused  mass  of  Sd  and  metal,  and  the  portion  of  the  Ch  im 
mediately  below  and  around  the  assay,  is  placed  in  the  little  agate 
mortar,  rubbed  to  powder,  the  powder  mixed  with  a  little  water, 
and  stirred  up.  The  heavy  metallic  particles  settle  to  the  bottom, 
part  of  the  Sd  dissolves,  and  the  Ch  powder  remains  suspended  in 
the  water.  The  liquid  is  carefully  poured  off,  and  the  residue 
treated  repeatedly  in  the  same  manner  until  all  foreign  matter  is 
removed.  The  metal  remains  behind  as  a  dark  heavy  powder  or, 
when  the  metal  is  ductile  and  easily  fusible,  in  the  shape  of  small 
flattened  scales  of  metallic  lustre.  If  the  substance  under  exami 
nation  contains  several  metallic  oxides,  the  metallic  mass  obtained 
is  usually  an  alloy,  in  which  the  several  metals  may  be  recognized 
by  processes  to  be  described  hereafter.  It  is  only  in  some  excep 
tional  cases  that  separate  metallic  globules  are  obtained,  ex.  gr.  in 
substances  containing  iron  and  copper. 

For  a  more  detailed  account  of  the  behavior  of  the  various 
metallic  oxides  under  this  treatment,  see  the  second  column  of 
Tables  I  and  II. 


BLOW-PIPE    ANALYSIS.  37 

§  41.  The  examination  with  Sd  is  usually  performed  on  Ch  in 
the  R  Fl,  and,  as  a  general  rule,  the  flux  is  added  successively  in 
small  portions.  This  is  particularly  necessary  when  the  assay  is 
to  be  tested  for  its  fusibility  with  Sd,  since  a  great  many  minerals, 
&c.,  behave  very  differently  with  different  quantities  of  the  flux. 

§  42.  Instead  of  carbonate  of  soda,  the  neutral  oxalatc  of  potassa 
or  cyanide  of  potassium  may  be  advantageously  used  for  all  experi 
ments  of  reduction,  since  these  reagents  exercise  a  more  powerful 
reducing  action  than  common  Sd.  They  are,  for  this  reason,  fre 
quently  employed  when  the  presence  of  such  metallic  oxides  is  sus 
pected,  whose  conversion  into  metals  require  high  temperatures 
and  the  aid  of  a  very  efficient  deoxidizing  agent. 

Examination  with  Solution  of  Cobalt. 

§  43.  A  few  substances,  when  moistened  with  a  solution  of  nitrate 
of  cobalt  and  exposed  to  the  action  of  the  0  Fl,  assume  a  peculiar 
color.  The  use  of  this  test  is,  however,  very  limited,  since  the 
reaction  can  only  clearly  be  seen  in  such  bodies  which,  after 
having  been  acted  upon  by  the  0  Fl,  present  a  white  appearance, 
or  nearly  so. 

§  44.  Substances  which  are  sufficiently  porous  to  imbue  a  liquid, 
are  merely  moistened  with  a  drop  of  S  Co,  placed  into  the  platinum- 
pointed  pincers,  and  treated  with  the  0  Fl.  Other  substances  must 
be  powdered,  the  powder  placed  on  Ch,  wetted  with  a  drop  of  S 
Co,  and  treated  as  above.  The  color  can  only  be  distinguished 
after  cooling.  A  bluish  color,  of  more  or  less  purity,  indicates  the 
presence  of  alumina  [No.  21] ;  and  a  pale-reddish  color  [flesh-color] 
that  of  magnesia  [No.  59].  It  must,  however,  be  borne  in  mind, 
that  the  alkaline  and  some  other  silicates,  when  heated  with  S  Co 
to  a  temperature  above  their  fusing  point,  also  assume  a  blue  color, 
owing  to  the  formation  of  silicate  of  cobalt.  In  testing  for  alumina, 
therefore,  the  heat  must  not  be  raised  so  high  as  to  cause  fusion  of 
the  assay.  In  testing  for  magnesia  this  precaution  is  not  necessary ; 
on  the  contrary,  the  color  will  appear  the  brighter  and  the  more 
distinct,  the  higher  the  temperature  to  which  the  assay  was 
exposed. 
4 


38  ELDERHORST'S  MANUAL  OP 

§  45.  Among  the  oxides  of  the  heavy  metals,  those  of  zinc  and 
tin  assume  characteristic  colors  \vith  S  Co.  The  reaction  is  best 
seen  when  the  assay,  alone  or  mixed  with  Sd,  is  exposed  to  the  R 
Fl  on  Ch.  The  ring  of  oxide  which  is  deposited  around  the  assay 
is  then  moistened  with  S  Co  and  treated  with  the  0  Fl.  Oxide  of 
zinc  takes  a  fine  yellowish-green,  and  oxide  of  tin  a  bluish-green 
color  [No.  3G  &  No.  33]. 

§  46.  Besides  the  compounds  above  mentioned  there  are  some 
others  which,  when  exposed  to  the  action  of  S  Co  and  0  Fl,  expe 
rience  a  change  of  color.  These  bodies  are  either  of  very  rare 
occurrence,  or  the  change  produced  in  them  is  not  sufficiently  dis 
tinct.  It  will,  therefore,  be  sufficient  merely  to  mention  the  names 
of  the  compounds  and  the  color  which  S  Co  imparts  to  them : 

Baryta  [brownish-red],  tantalic  acid  [flesh-color],  zirconia  and 
phosphate  of  magnesia  [violet],  titanic  acid,  niobic  acid,  and  anti- 
monic  acid  [green],  strontia,  lime,  glucina,  and  pelopic  acid  [gray]. 


BLOW-PIPE    ANALYSIS.  39 


THIRD   CHAPTER. 

SPECIAL  REACTIONS  FOR  THE  DETECTION"  OF  CERTAIN  SUBSTANCES 
WHEN   IN   COMBINATION   WITH   OTHERS. 

§  47.  THE  preceding  chapter  and  accompanying  table  show  the 
changes  which  many  of  the  simple  chemical  compounds  undergo 
when  heated,  or  when  treated  with  the  usual  blow-pipe  reagents. 
The  reactions  are  sufficiently  characteristic  to  distinguish  the 
various  compounds  from  each  other,  so  that,  when  any  of  the 
above  named  substances  in  a  pure  state  is  under  examination, 
there  is  no  difficulty  to  determine  its  nature.  This,  however,  is 
not  of  frequent  occurrence,  and  in  the  majority  of  cases  the  body  to 
be  tested  will  be  of  a  more  complex  nature.  The  results  of  the 
experiments  will  vary  accordingly.  For  instance,  an  ore  of  cobait. 
containing  iron,  will  not  impart  to  the  bead  of  Bx  or  S  Ph  in  the 
0  Fl  a  blue  color,  but  a  green  one,  resulting  from  the  mixture  of 
the  blue  of  cobalt  and  the  yellow  of  iron ;  lead,  when  accompanied 
by  antimony,  deposits  a  dark-yellow  coating  on  Ch  resembling  that 
of  bismuth,  &c.  In  such  cases  we  may  often,  by  attentively  ob 
serving  all  the  phenomena  which  present  themselves,  and  by  care 
fully  comparing  the  results  obtained  by  the  various  experiments, 
detect  many,  if  not  all,  of  the  components  of  the  substance  under 
examination.  Sometimes  we  attain  this  end  quicker  by  varying 
the  order,  or  by  introducing  auxiliary  agents  into  the  series  of 
experiments ;  and  in  other  cases,  again,  it  is  only  to  be  arrived  at 
by  subjecting  the  assay  to  treatments  different  from  those  men 
tioned  in  the  preceding  pages. 

This  chapter  contains  the  principal  reactions  for  the  detection  of 
substances  which  require  the  application  of  peculiar  agents,  and  the 
methods  for  ascertaining  the  presence  of  certain  bodies  when  in 
combination  with  others.  The  alphabetical  arrangement  will  be. 
found  of  practical  use. 

(30) 


40  ELDERHORST'S  MANUAL  OF 

Ammonia. 

§  48.  Small  quantities  of  ammonia  arc  best  detected  by  mixing 
the  powdered  assay  [No.  19]  with  some  carbonate  of  soda  or 
caustic  potassa,  introducing  the  mixture  into  a  glass  tube,  scaled 
at  one  end,  and  applying  heat.'  The  escaping  gas  is  characterized 
by  its  odor,  and  by  it^s  action  on  reddened  litmus  paper.  From 
the  appearance  of  this  reaction  we  are,  however,  not  authorized  to 
infer  the  prcexistence  of  ammonia  in  the  assay,  since  from  organic 
matter  containing  nitrogen,  when  subjected  to  this  treatment, 
ammonia  is  evolved  as  a  product  of  decomposition. 

Antimony. 

The  reactions  of  antimony  and  its  compounds,  see  §  11,  §  16,  §  21, 
§  36,  and  Table  II,  1. 

§  49.  In  presence  of  lead  or  bismuth,  antimony  can  not  be  detected 
by  its  Ct  on  Ch.  In  this  case  the  metallic  compound  [Xo.  48,  or 
Xo.  85]  is  treated  with  vitrified  boracic  acid  on  Ch,  the  flame  being 
so  directed  that  the  glass  is  always  kept  covered  with  the  blue 
cone,  the  metallic  globule  being  on  the  side  ;  by  this  means  the 
metals  become  oxidized,  the  oxides  of  lead  and  bismuth  are  ab 
sorbed  by  the  boracic  acid,  and  the  antimonious  acid  will  form  a 
ring  on  the  Ch,  provided  the  temperature  was  not  raised  too  high. 

§  50.  When  combined  with  metals  from  which  it  is  not  easily 
separated,  ex.  gr.  copper,  the  evaporation  of  the  antimony  takes 
place  so  slowrly  that  no  distinct  Ct  is  produced.  In  this  case  the 
assay  [No.  86]  is  treated  with  S  Ph  on  Ch  in  the  0  Fl,  until  the 
antimony,  or  at  least  part  of  it,  has  become  oxidized  and  entered 
into  the  flux.  The  glass  is  now  removed  from  the  metallic  globule 
and  treated  on  another  place  of  the  Ch  with  metallic  tin  in  the 
II  Fl ;  the  presence  of  antimony  will  cause  the  glass  to  turn  gray 
or  black  on  cooling  [Table  II,  1].  Bismuth  behaving  under  these 
circumstances  in  the  same  manner,  the  presence  of  this  metal 
makes  the  reaction  not  decisive  for  antimony.  The  humid  way 
has  then  to  be  resorted  to. 

§  51.  When  the  oxides  of  antimony  are  accompanied  by  such 
metallic  oxides  which,  when  reduced  on  Ch,  fuse  with  the  metallic 
antimony  to  an  alloy,  as  is  ex.  gr.  the  case  with  the  oxides  of  tin 


BLOW-PIPE    ANALYSIS.  41 

and  copper,  the  latter  cannot  be  recognized  by  a  simple  reduction. 
The  oxides  have  to  be  treated  with  a  mixture  of  Sd  and  Bx  on  Ch 
in  the  R  Fl.  The  little  metallic  globules  are  separated  from  the 
flux,  and  fused  with  from  three  to  five  times  their  own  volume  of 
pure  lead  and  some  vitrified  boracic  acid  in  the  R  Fl,  care  being 
taken  to  play  with  the  flame  only  on  the  glass.  Antimonious  acid 
is  volatilized,  depositing  the  characteristic  ring,  while  the  oxides 
of  the  other  metals  are  absorbed  by  the  boracic  acid. 

§  52.  The  sulphides  of  antimony,  when  heated  in  the  open  glass 
tube,  show  the  reaction  mentioned  §  16.  When  accompanied  by 
sulphide  of  lead  [Xo.  89],  only  a  small  part  of  the  antimony  is 
converted  into  antimonious  acid,  which  sublimes  ;  the  remainder  is 
changed  into  a  white  powder  consisting  of  a  mixture  of  antimonate 
of  oxide  of  antimony,  sulphate  of  lead,  and  antimonate  of  lead. 
When  a  compound  containing  sulphide  of  lead  or  bismuth,  besides 
sulphide  of  antimony,  is  heated  on  Ch  in  the  R  Fl,  a  Ct  is  deposited 
consisting  of  antimonious  acid  mixed  with  sulphate  of  lead  or  bis 
muth,  and,  nearer  to  the  assay,  a  yellow  one  of  the  oxides  of  lead 
or  bismuth  j  how  in  such  a  case  the  presence  of  antimony  may  be 
ascertained  v.  §  87. 

§  53.  To  detect  a  small  amount  of  sulphide  of  aitimrn.'  in  sul 
phide  of  arsenic,  Plattner  strongly  recommends  the  following 
method,  by  which  he  obtained  very  decisive  and  satisfactory  re 
sults  :  The  assay  [No.  88]  is  introduced  into  a  glass  tube,  sealed 
at  one  end,  and  gently  heated  ;  the  sulphide  of  arsenic  is  volatilized, 
and  the  greater  part  of  the  sulphide  of  antimony  remains  as  a 
black  powder  in  the  lower  end  of  the  tube  ;  this  end  is  cut  off, 
the  black  substance  taken  out  and  transferred  to  a  tube  open  at 
both  ends.  By  applying  heat  the  characteristic  antimony-reaction 
will  appear. 

Arsenic. 

The  reactions  of  arsenic  and  its  compounds,  see  §  11,  §  15,  §  20, 
§  34,  and  Table  II,  2. 

§  54.  All  metallic  arsenides  yield,  when  heated  in  the  open  glass 
tube,  a  sublimate  of  arsenous  acid  (v.  §  15),  and  most  of  them 
evolve  a  garlic  odor  (v.  §  20)  when  heated  on  Ch  in  R  Fl  [No.  77]. 


42  ELDERHORST'S  MANUAL  OP 

Some  metals,  ex.  gr.  nickel  and  cobalt,  have  a  great  affinity  for 
arsenic,  so  that,  when  only  a  small  quantity  of  the  latter  is  present, 
the  characteristic  odor  is  not  observable  ;  in  such  cases  it  is  some 
times  produced  when  the  metallic  compound  is  fused  on  Ch  with 
some  pure  lead  in  the  0  Fl. 

§  55.  The  sulphides  of  arsenic,  heated  in  the  open  glass  tube, 
evolve  sulphurous  acid  and  yield  a  sublimate  of  arsenous  acid.  To 
show  in  a  very  decisive  manner  the  presence  of  arsenic  in  any  of 
its  combinations  with  sulphur,  the  powdered  assay  [No.  80]  is 
mixed  with  six  parts  of  a  mixture  of  equal  parts  of  cyanide  of 
potassium  and  carbonate  of  soda,  the  mass  introduced  into  a  tube 
sealed  at  one  end,  and  heat  applied,  at  first  very  gently  but  gradu 
ally  raised  to  redness.  A  ring  of  metallic  arsenic  will  be  deposited 
in  the  colder  part  of  the  tube 

§  56.  When  sulph-arsenides  are  heated  on  Ch,  the  whole  of  the 
arsenic,  especially  when  only  small  quantities  are  present,  may  pass 
off  in  combination  with  sulphur;  but  when  such  compounds  [No.  88] 
are  mixed  with  from  three  to  four  parts  of  cyanide  of  potassium  and 
exposed  to  the  R  Fl,  sulphide  of  potassium  is  formed  and  the 
arsenic  escapes  with  its  peculiar  odor. 

§  57.  To  detect  a  very  small  quantity  of  arsenous  acid,  the  fol 
lowing  way  may  be  pursued:  a  glass  tube  provided  with  a  small 
bulb  at  one  end  is  close  above  it  narrowly  drawn  out;  the  assay 
[No.  38]  is  introduced  into  the  bulb,  and  a  charcoal  splinter  placed 
into  the  tube;  the  narrow  aperture  through  which  the  tube  com 
municates  with  the  bulb  prevents  the  Ch  from  earning  in  contact 
with  the  substance.  The  tube  is  then  heated  to  redness  at  the 
place  where  the  charcoal  splinter  lies,  and  as  soon  as  this  is  incan 
descent,  heat  is  also  applied  to  the  bulb.  The  arsenous  acid  is 
volatilized,  and  its  vapors,  while  passing  over  the  red-hot  charcoal, 
become  reduced  and  deposit  a  black  metallic  ring  of  arsenic  in  the 
colder  part  of  the  tube.  By  cutting  the  tube  below  the  r'ng  and 
heating  this  part  by  the  flame  of  a  spirit-lamp,  the  arsenic  is  vola 
tilized,  thereby  emitting  its  characteristic  odor. 

§  58.  To  show  the  presence  of  arsenic  in  arsenites  and  arsenatcs, 
it  will  in  most  cases  be  sufficient  to  mix  the  substance  [No.  38] 
with  carbonate  of  soda  and  heat  it  on  Ch  in  K  Fl.  Sometimes  it 


BLOW-PIPE    ANALYSIS.  43 

is  necessary  to  treat  the  assay  with  a  mixture  of  carbonate  of  soda 
and  cyanide  of  potassium  in  the  manner  mentioned,  §  55 ;  and  in 
other  cases  again,  where  but  small  quantities  of  arsenous  or  arsenic 
acid  are  combined  with  metallic  oxides  which  are  readily  reduced, 
recourse  must  be  had  to  the  humid  wray. 

Bismuth. 

The  reactions  of  bismuth  and  its  compounds,  see  §  12,  §  17,  §  22, 
and  Table  II,  3. 

§  59.  Bismuth  when  alloyed  with  other  metals,  or  when  as  sul 
phide  in  combination  with  other  sulphides,  is  in  many  cases,  and 
most  especially  so  when  accompanied  by  lead  or  antimony,  not  to 
be  detected  by  the  ring  which  it  deposits  on  Ch.  In  such  a  case 
the  assay  [No.  49]  is  treated  on  Ch  until  a  copious  yellow  Ct  is 
formed.  The  Ct  is  carefully  scraped  off  from  the  Ch  and  dissolved 
in  S  Ph  on  platinum  wire  with  the  0  Fl.  The  colorless  bead  is 
removed  from  the  wire,  placed  on  Ch,  a  little  metallic  tin  added, 
and  the  whole  exposed  to  the  R  Fl.  If  bismuth  was  present,  the 
glass  assumes,  on  cooling,  a  dark-gray  or  black  color.  The  oxides 
of  antimony  showing  the  same  behavior,  the  assay,  if  not  quite 
free  from  antimony,  has  to  be  treated  on  Ch  in  the  0  Fl  until  the 
whole  of  it  has  been  volatilized,  and  the  remaining  mass  treated  on 
another  piece  of  Ch  as  above  mentioned. 

Boracic  Add. 

§  60.  With  many  borates,  which  do  not  impart  to  the  outer  flame 
the  peculiar  yellowish-green  color  [v.  §  35],  this  reaction  may  be 
produced  by  reducing  the  substance  [No.  2]  to  powder,  adding  a 
drop  of  concentrated  sulphuric  acid,  fastening  the  mixture  into  the 
hook  of  the  platinum  wire,  and  playing  on  it  with  the  blue  cone  of 
the  flame. 

§  61.  Another  way,  and  by  which  even  a  very  small  quantity  of 
boracic  acid  in  salts  and  minerals  maybe  detected,  is:  to  reduce  the 
substance  to  a  very  fine  powder,  to  mix  it  with  from  3  to  4  parts 
of  a  mixture  of  4J  parts  of  bisulphate  of  potassa  and  1  part  of  fluor 
spar,  and  to  knead  the  whole  with  a  little  wrater  into  a  thick  paste. 
This  mass  is  then  fastened  to  a  platinum  wire,  and  exposed  to  the 
blue  cone  of  the  flame.  While  the  mass  enters  into  fusion  fluoboric 


44  ELDERHORST'S  MANUAL  OF 

acid  is  formed  which,  on  escaping,  colors  the  flame  intensely  yel 
lowish-green.  The  reaction  appearing  sometimes  only  for  a  few 
seconds,  the  flame  should  be  very  attentively  watched  during  the 
whole  time  of  the  experiment. 

Bromine. 

§  G2.  Bromides  treated  with  S  Ph  and  oxide  of  copper  on  pla 
tinum  wire,  or  treated  with  sulphate  of  copper  on  silver  foil,  show 
the  same  reaction  as  chlorides  (v.  §  6G),  with  this  difference,  that 
the  blue  color  of  the  outer  flame  is  rather  greenish,  especially  on 
the  edges  [No.  16]. 

§  63.  To  discriminate  bromides  from  chlorides  more  distinctly, 
the  bromide  is  fused  with  bisulphatc  of  potassa,  both  in  the  anhy 
drous  state,  in  a  small  matrass  with  long  neck.  Sulphurous  acid 
is  evolved,  and  the  matrass  is  filled  with  yellow  vapors  of  bromine, 
characterized  by  their  peculiar  odor.  The  color  of  the  gas  is  only 
clearly  seen  at  daylight. 

Cadmium. 

The  reactions  of  cadmium  and  its  compounds,  sec  §§  11,  24,  and 
Table  II,  4. 

§  64.  To  detect  a  very  small  quantity  of  cadmium,  one  per  cent, 
or  less,  in  zinc  or  its  ores,  the  pulverized  assay  is  mixed  with  Sd 
and  exposed  for  a  short  time  to  the  H  Fl  on  Ch.  A  distinct  Ct  of 
oxide  of  cadmium  is  deposited.  The  zinc  being  less  volatile,  evapo 
rates  only  with  continued  blowing  [No.  53]. 
Chlorine. 

§  G5.  Some  oxide  of  copper  is  dissolved  by  means  of  the  0  Fl  in 
a  bead  of  S  Ph  on  platinum  wire,  until  it  has  assumed  a  deep-green 
color.  Some  grains  of  the  pulverized  assay  [No.  18]  are  then  made 
to  adhere  to  the  bead,  and  both  heated  with  the  blue  cone  of  the 
flame.  If  chlorine  is  present  the  flame  now  assumes  an  intense 
azure-blue  color,  owing  to  the  formation  of  chloride  of  copper  (v.  §  36). 
This  test  is  very  delicate,  and  will  show  the  presence  of  a  very  mi 
nute  quantity  of  chlorine. 

§  66.  Another  method  is  to  place  on  silver-foil  some  protosulphatc 
of  iron,  or  some  sulphate  of  copper,  to  moisten  it  with  a  drop  of 
water,  and  then  to  add  the  assay  [No.  18].  After  a  while  the 


BLOW-PIPE    ANALYSES.  45 

silver  will  be  found  blackened.  Substances  which  are  insoluble  in 
water  have  previously  to  be  fused  with  a  little  Sd  on  platinum  wire, 
to  form  a  soluble  chloride  [No.  10]. 

Chlorides,  when  moistened  with  sulphuric  acid  and  exposed  to 
the  BIp  flame,  impart  to  it  a  faint  green  coloration  which,  however, 
is  generally  confined  to  the  inner  cone,  and  is  quantitatively  of 
much  less  intensity  than  that  produced  with  borates.  A  small 
amount  of  boracic  acid,  when  occurring  together  with  a  chloride, 
can,  therefore,  not  be  detected  by  the  method  mentioned  §  60. 

Chromium. 

§61.  Oxide  of  chromium  gives  very  characteristic  reactions  with 
the  fluxes  on  platinum  wire  (v.  Table  II,  6),  but  when  accompanied 
by  a  large  quantity  of  iron,  copper,  or  other  substances  which  also 
intensely  color  the  Bx  and  S  Ph  beads,  the  chromium  color  fre 
quently  becomes  very  indistinct. 

§  68.  In  such  a  case,  and  when  the  chromium  is  not  in  combina 
tion  with  silicic  acid,  its  presence  may  be  detected  in  the  following 
manner:  The  assay-piece  [Xo.  11]  is  reduced  to  a  fine  powder  and 
mixed  with  about  four  times  its  own  volume  of  a  mixture  of  equal 
parts  of  Sd  and  nitre.  The  mass  is  fastened  into  the  hook  of  a 
thick  platinum  wire,  or  placed  into  a  small  platinum  spoon,  and 
treated  with  a  powerful  0  Fl.  An  alkaline  chromate  is  formed 
which  is  dissolved  in  water,  the  solution  supersaturated  with  acetic 
acid,  and  a  crystal  of  acetate  of  lead  added.  If  chromium  was  pres 
ent,  a  yellow  precipitate  of  chromate  of  lead  will  appear.  The 
precipitate  may  be  collected  on  a  filter  and  tested  in  the  Bx  and  S 
Ph  beads,  when  the  characteristic  chromium-reactions  will  be  pro 
duced. 

Cobalt. 

The  reactions  of  cobalt,  see  Table  II,  1. 

§  69.  To  detect  cobalt  when  in  combination  with  other  metals, 
v.  §  83. 

To  show  its  presence  in  arsenides,  the  assay  [Xo.  18]  is  placed 
on  Ch  and  heated  until  no  longer  fumes  of  arsenous  acid  are  emit 
ted.  (Lead  and  bismuth,  if  present,  form  the  characteristic  coat 
ings.)  Bx  is  now  added  and  the  heat  continued  until  the  glass 


46  ELDEHHORST'S  MANUAL  OF 

appears  colored.  If  the  color  is  not  pure  blue,  the  presence  of  iron 
is  indicated.  The  glass  is  in  this  case  removed  from  the  globule, 
and  the  latter  treated  repeatedly  with  fresh  quantities  of  Bx  until 
the  pure  cobalt-color  is  obtained.  Nickel  and  copper,  if  present,  do 
not  enter  into  the  flux  before  the  whole  of  the  cobalt  is  oxidized. 
If  we  wish  to  ascertain  the  presence  of  these  metals,  the  glass  which 
is  colored  by  cobalt  is  removed  from  the  globule,  and  the  latter 
treated  with  fresh  portions  of  Bx  in  the  0  Fl  until  the  color  of  the 
bead  becomes  brown,  indicative  of  nickel.  The  glass  is  again 
removed  and  the  globule  treated  with  S  Ph  in  the  0  Fl;  when  cop 
per  is  present  the  bead  assumes  a  green  color,  which  remains  unal 
tered  on  cooling.  Treated  with  tin  on  Ch  the  glass  turns  opaque 
and  red. 

§  70.  To  detect  cobalt  in  sulphides,  the  assay  [No.  79]  is  heated 
on  Ch  in  the  II  Fl  until  all  volatile  substances  are  driven  off,  the 
remaining  mass  reduced  to  powder,  well  calcined,  and  the  calcined 
mass  treated  with  Bx  on  Ch  in  the  0  Fl.  If  cobalt  is  the  only 
coloring  metal  present,  the  bead  will  exhibit  a  pure  blue  color  •  a 
small  addition  of  iron  will  make  the  glass  appear  green  while  hot, 
but  blue  when  cold.  Copper  and  nickel,  when  present  to  some  ex 
tent,  will  prevent  the  cobalt-color  to  be  distinctly  seen.  The  bead 
is  in  this  case  exposed  to  the  K  Fl  until  it  appears  transparent  and 
flows  quietly ;  the  oxides  of  copper  and  nickel  are  by  this  means 
reduced,  and  the  pure  color  of  cobalt,  or  that  of  cobalt  mixed  with 
iron,  becomes  apparent. 

Copper. 

The  reactions  of  copper  and  its  compounds,  see  §§  35,  3G,  and 
Table  II,  8. 

§  71.  The  red  color  which  copper  imparts  to  the  Bx  or  S  Ph 
bead,  when  heated  on  Ch  in  the  II  Fl  in  contact  with  tin  (v.  Table 
II,  8),  is  very  characteristic  and  will  in  most  cases  clearly  show  the 
presence  of  this  metal.  But  if  only  a  small  quantity  of  copper  is 
associated  with  other  metals,  the  reaction  is  not  easily  obtained ; 
in  this  case  we  may  proceed  as  follows  : 

The  assay  [No.  89,  or  No.  8G,  or  No.  85]  is  placed  on  Ch  and  played 
upon  with  the  0  Fl  until  antimony  and  other  volatile  metals  arc  driven 


BLOW-PIPE   ANALYSIS.  47 

off.  Some  vitrified  boracic  acid  is  fused  on  Ch  to  a  glassy  globule, 
the  assay  placed  close  to  it,  and  the  whole  covered  with  a  large  R 
Fl.  When  the  metallic  globule  begins  to  assume  a  bright  metallic 
surface,  the  flame  is  gradually  converted  into  a  sharply-pointed  blue 
cone,  which  is  made  to  act  only  on  the  glass,  leaving  the  metallic 
globule  untouched,  and  so  situated  that  it  touches  the  glass  on  one 
side,  and  on  the  other  side  is  in  close  contact  with  the  Ch.  During 
this  process  lead,  iron,  cobalt,  part  of  the  nickel,  and  such  of  the 
more  volatile  metals,  that  were  not  entirely  removed  by  the  pre 
vious  calcination,  as  bismuth,  antimony,  zinc,  &c.,  become  oxidized, 
and  their  oxides  partly  volatilized  and  partly  absorbed  by  the 
boracic  acid.  The  remaining  metallic  globule  is  then  removed  from 
the  flux  and  treated  on  Ch  with  S  Ph  in  the  0  Fl,  when  the  copper 
is  oxidized  and  dissolved.  The  limpid  bead  is  then  re-fused  in  the 
R  Fl  with  addition  of  tin.  A  trace  of  copper  may  thus  be  made  to 
produce  distinctly  the  characteristic  reaction. 

§72.  To  show  the  presence  of  copper  in  compounds  which  con 
tain  much  nickel,  cobalt,  iron,  and  arsenic,  the  assay  [No.  82]  is 
first  treated  with  Bx  on  Ch  in  the  R  Fl,  when  the  greater  part  of 
iron  and  cobalt  are  dissolved.  The  remaining  globule  is  then  mixed 
with  some  pure  lead,  and  treated  as  shown  §  71.  Arsenic  is  for  the 
most  part  driven  off,  and  the  rest  of  the  iron  and  cobalt,  with  some 
nickel,  absorbed  by  the  boracic  acid.  The  globule  is  removed  from 
the  glass  and  treated  with  S  Ph  in  the  0  Fl ;  dark-green  while  hot, 
and  somewhat  lighter  green  when  cold  (produced  by  the  mixture 
of  the  yellow  of  nickel  and  the  blue  of  copper),  indicates  the  presence 
of  copper. 

To  detect  copper  when  in  combination  with  tin  v.  §  110. 

§  73.  To  detect  copper  in  sulphides,  the  pulverized  assay  [No. 
76]  is  calcined,  and  the  calcined  mass  treated  as  above,  or,  when 
the  amount  of  copper  is  not  very  small,  simply  treated  with  Bx  or 
S  Ph  on  Ch  in  the  0  Fl,  and  subsequently  with  addition  of  tin  in 
the  R  Fl.  The  presence  of  copper  is  then  shown  by  the  red  color  and 
the  opaqueness  of  the  glass  on  cooling.  This  reaction  is  only  pre 
vented  or,  at  least,  made  indistinct  by  antimony  or  bismuth,  which 
cause  the  glass  to  turn  gray  or  black.  In  this  case  the  assay  is, 
after  calcination,  mixed  with  Sd,  Bx,  and  some  pure  lead,  and  the 


43  ELDERIIORST'S  MANUAL  OF 

mixture  fused  on  Ch  in  the  R  Fl.  The  metallic  globule  is  then 
heated  on  Ch  to  drive  off  the  antimony,  and  afterwards  treated  with 
boracic  acid  as  above. 

§  74.  When  a  mineral  which  contains  copper  is  heated  in  the 
blue  cone,  the  outer  cone  of  the  flame  frequently  assumes  a  green 
or,  if  the  metal  is  in  combination  with  chlorine,  an  azure-blue  color. 
This  reaction,  if  not  produced  by  heating  the  substance  alone,  may 
sometimes  be  elicited  by  adding  a  drop  of  concentrated  hydrochloric 
acid  to  the  pulverized  assay  [No.  73],  evaporating  to  dryncss, 
mixing  the  dry  powder  with  a  little  water  to  a  stiff  paste,  fastening 
this  into  the  hook  of  a  platinum  wire,  and  then  exposing  it  to  the 
blue  cone  of  the  flame. 

Fluorine. 

§  75.  To  detect  fluorine  in  such  minerals  where  it  occurs  oi\]y  as 
an  accessory  element  in  combination  with  weak  bases,  and  which 
at  the  same  time  contain  water,  a  small  piece  of  the  substance  [No. 
00]  is  placed  into  a  glass  tube  scaled  at  one  end,  a  wet  Brazil-wood 
paper  introduced  into  the  open  end,  and  heat  applied.  Fluoride  of 
silicon  and  hydrofluoric  arc  evolved;  the  former  is  decomposed  by 
the  watery  vapor  and  deposits  a  ring  of  silica  not  far  distant  from 
the  assay,  and  the  latter  turns  the  red  color  of  the  test-paper  into 
straw-yellow.  Mica,  containing  not  more  than  J  per  cent,  of  fluo 
rine  shows  the  reaction  very  distinctly. 

§  7G.  To  show  the  presence  of  fluorine  in  minerals  where  it  is 
united  with  strong  bases,  the  finely  powdered  assay  [No.  G]  is 
mixed  with  about  four  parts  of  bisulphatc  of  potassa  and  intro 
duced  into  a  glass  tube,  sealed  at  one  end.  Heat  is  applied  until 
sulphuric  acid  begins  to  escape.  The  sides  of  the  tubes  become 
covered  with  silicic  acid,  resulting  from  the  decomposition  of  the 
gaseous  fluoride  of  silicon.  The  tube  is  cut  off  clo^e  above  the 
fused  mass,  cleaned  with  water,  and  carefully  dried  with  blotting 
paper.  The  dulled  appearance  of  the  glass  indicates  the  presence 
uf  fluorine. 

§  77.  Another  process,  and  by  which  the  presence  of  fluorine  in 
all  kind  of  compounds  may  be  shown,  is  to  mix  the  pulverized 
assay  with  some  S  Ph  which  has  previously  been  fused  on  Ch  and 


BLOW-PIPE    ANALYSIS.  49 

then  reduced  to  powder;  to  place  the  mixture  on  platinum  foil, 
which  is  connected  with  an  open  glass  tube  in  such  a  manner  as  to 
constitute  a  kind  of  tubular  continuation  to  the  former,  and  to  heat 
with  the  blow-pipe  flame  until  the  mass  enters  into  fusion.  If  the 
flame  is  so  directed  that  the  products  of  decomposition  are  made 
to  pass  through  the  glass  tube  and  a  moistened  Brazil-wood  paper 
is  introduced  into  the  other  end,  the  presence  of  hydrofluoric  acid 
is  indicated  by  the  change  of  color  which  the  latter  experiences; 
in  some  cases  the  glass  will  also  be  dulled,  or  a  deposit  of  silicic 
acid  be  formed.  This  test  is  very  delicate. 

Gold. 

§78.  When  gold  is  in  combination  with  metals  which  are  volatile 
at  a  high  temperature,  ex.  gr.  tellurium,  mercury,  antimony,  it  is 
only  necessary  to  heat  the  alloy  on  Ch  with  the  0  Fl,  when  the 
gold  remains  behind  in  a  pure  state  and  may  be  recognized  by  its 
physical  properties.  Lead  is  removed  by  the  process  of  cupellation, 
as  explained  in  §  102.  , 

§  79.  When  associated  with  copper,  the  presence  of  which  is 
easily  detected  by  S  Ph  on  Ch,  the  alloy,  for  example  gold-coin,  is 
dissolved  in  pure  melted  lead  and  the  new  compound  subjected  to 
the  process  of  cupellation  on  bone-ash.  Copper  is  by  this  means 
entirely  removed.  To  test  the  remaining  globule  for  silver,  it  is 
treated  with  S  Ph  on  Ch  in  the  0  Fl;  the  silver  is  gradually  oxi 
dized  and  dissolved  by  the  glass,  which  when  cold  assumes  an 
opal-like  appearance.  To  determine  approximately  the  relative 
proportions  of  the  two  metals,  the  metallic  globule  is  taken  from 
the  cupel,  placed  in  a  small  porcelain  dish,  containing  some  nitric 
acid,  and  heat  applied.  If  the  alloy  contains  25  per  cent,  of  gold 
or  less,  it  turns  black,  the  silver  is  gradually  dissolved  and  the  gold 
remains  behind  as  a  brown  or  black  spungy  or  pulverulent  mass. 
If  the  alloy  contains  more  than  25  per  cent,  of  gold,  the  globule 
turns  also  black,  but  the  silver  is  not  dissolved.  If  both  metals  are 
present  in  about  equal  proportions,  the  globule  remains  unaltered. 
If  the  amount  of  gold  is  considerable  it  is  indicated  by  the  color  of 
the  alloy. 

§  80.  When  associated  with  metals,  which  per  se  are  infusible 
5  D 


50  ELDERIIORST'S  MANUAL  OF 

before  the  blow-pipe,  as  ex.  gr.  platinum,  indium,  palladium,  the 
metallic  globule  obtained  by  cupellation  shows  much  less  fusibility 
than  pure  gold.  The  exact  nature  of  the  foreign  metals  cannot  be 
ascertained  before  the  Blp ;  the  humid  way  must  be  resorted  to. 

Iodine. 

§  81.  Iodides,  tested  with  a  S  Ph  bead  which  is  saturated  with 
oxide  of  copper  as  shown  §  65,  impart  to  the  outer  flame  a  fine 
green  color  [No.  I1?]. 

Fused  with  bisulphate  of  potassa  in  a  glass  tube,  closed  at  one 
end,  violet  vapors  are  evolved,  iodine  sublimes,  and  sulphurous 
acid  escapes. 

§  82.  Another  method,  which  is  said  to  surpass  in  delicacy  even 
the  reaction  with  starch,  is  to  mix  the  substance  with  a  mixture 
of  carbonate  of  lime  and  quicklime,  to  dry  the  mass  thoroughly, 
to  add  some  protochloride  of  mercury  (corrosive  sublimate),  to  rub 
the  whole  well  together,  and  to  place  it  in  a  glass  tube  closed  at 
one  end.  The  tube  is  then  narrowly  drawn  out  a  little  above  the 
assay,  and  the  mass  heated  to  redness.  Protiodidc  of  mercury  is 
formed,  which  sublimes  in  yellow  or  red  needles  into  the  narrow 
tube.  This  reaction  is  founded  on  the  property  of  lime  to  decom 
pose  the  protochloride  of  mercury,  but  not  the  protiodide. 

Iron. 

The  reactions  of  the  oxides  of  iron,  see  Table  II,  10. 

§  83.  The  colors  which  iron  imparts  to  the  various  fluxes  are 
sufficiently  characteristic  to  ascertain  its  presence  in  such  metallic 
compounds  which  contain  no  easily  fusible  substances,  by  simply 
treating  the  assay  with  Bx  on  Ch  in  the  0  Fl.  When  lead,  tin, 
bismuth,  antimony,  or  zinc  are  present,  the  II  Fl  is  employed,  and 
directed  in  such  a  manner  that  it  principally  touches  the  glass. 
Thus,  the  oxidation  and  consequent  saturation  of  the  bead  with ' 
the  oxides  of  these  metals,  is  to  a  great  extent  prevented.  In 
either  case  the  glass,  while  still  soft,  is  removed  from  the  globule 
and  exposed  on  another  place  of  the  Ch  to  the  R  Fl.  Those  metals 
whose  oxides  are  easily  reduced,  are  now  precipitated,  and  the 
characteristic  bottle-green  color  of  iron  is  clearly  observable,  unless 
cobalt  be  present,  In  this  case  the  glass  is  again  softened  with 


BLOW-PIPE    ANALYSIS.  51 

the  II  Fl,  separated  from  the  precipitated  metals,  fastened  into  the 
hook  of  a  platinum  wire  and  treated  with  the  O  Fl  until  the  whole 
of  the  iron  may  be  supposed  to  be  converted  into  sesquioxide.  The 
glass,  while  hot,  will  appear  green,  and  blue  when  cold,  if  only  a 
trace  of  iron  is  present.  But  when  the  amount  of  iron  is  more 
considerable,  it  will  be  dark-green  while  hot  and  bright-green  when 
cold,  the  latter  color  resulting  from  the  mixture  of  the  blue  of 
cobalt  and  the  yellow  of  iron.  The  metals  remaining  behind  on 
Ch  after  the  treatment  with  Bx,  and  which  frequently  are  only 
copper  and  nickel  (lead,  antimony,  and  bismuth  being  volatilized), 
may  be  treated  as  shown  §71. 

To  detect  iron  in  arsenides  and  sulphides,  the  assay  is  well  cal 
cined,  and  the  calcined  mass  treated  as  above  [No.  86  and  No.  79]. 

§  84.  The  oxides  of  iron  when  associated  with  a  large  quantity 
of  manganese  [No.  84  and  No.  69],  color  the  Bx  bead  on  platinum 
wire  in  the  O  Fl,  red.  To  show  the  presence  of  iron  the  bead  is 
removed  from  the  wire,  placed  on  Ch,  and  treated  with  tin  in  the 
R  Fl.  The  vitriol-green  color  of  iron  will  appear  in  its  purity. 
When  associated  with  the  oxides  of  manganese  and  cobalt,  a  minute 
quantity  of  iron  cannot  very  well  be  detected  by  means  of  the  blow 
pipe  alone.  When  accompanied  by  the  oxides  of  copper  and  nickel 
[No.  78  or  No.  85],  the  assay  is  dissolved  in  Bx  on  Ch  in  the  0  Fl 
and  the  glass  treated  as  shown  §  83. 

§  85.  The  presence  of  chromium  prevents  any  conclusive  deduc 
tion  as  to  the  presence  of  iron  from  the  color  of  the  beads.  In  such 
a  case  the  substance  [No.  71]  may  be  mixed  with  three  parts  of 
nitre  and  one  of  Sd,  and  the  mixture  fused  in  small  portions 
into  the  hook  of  a  thick  platinum  wire.  The  alkaline  chrornate  is 
dissolved  in  water  and  the  residue  treated  with  the  fluxes.  The 
presence  of  the  oxides  of  iron  when  associated  with  the  oxides  of 
uranium  cannot  be  ascertained  by  means  of  the  blow-pipe  alone. 

Lead. 

The  reactions  of  lead  and  its  compounds,  see  §§  12,  23,  36,  and 
Table  II,  12. 

§  86.  An  alloy  of  lead  and  zinc  [No.  50]  deposits  a  Ct  of  oxide 
of  lead  mixed  with  oxide  of  zinc;  the  presence  of  lead  is  shown 


52  ELDERHORST'S  MANUAL  OF 

by  the  color  of  the  Ct  and  by  the  azure-blue  tinge  which  it  imparts 
to  the  R  Fl  (v.  §  23). 

An  alloy  of  lead  and  bismuth  [No  49]  deposits  a  Ct  somewhat 
darker  than  that  of  pure  lead,  in  which  the  presence  of  bismuth 
may  be  detected  as  shown  §  59,  and  the  presence  of  lead  by  the 
azure-blue  color  of  the  R  Fl. 

§  87.  To  detect  lead  in  sulphides,  the  substance  is  placed  on  Ch 
and  treated  with  the  R  Fl ;  the  lead  is  detected  by  its  Ct.  An 
admixture  of  antimony  cannot  by  this  means  be  ascertained,  since 
the  ring  of  sulphate  of  lead,  surrounding  that  of  the  oxide,  bears 
p.  striking  resemblance  to  the  Ct  formed  by  antimonious  acid.  In 
this  case  the  pulverized  assay  [No.  85]  is  mixed  with  a  sufficient 
quantity  of  Sd,  and  treated  for  a  short  time  with  the  R  Fl.  If  no 
antimony  is  present  a  pure  yellow  Ct  with  bluish-white  edges  is 
formed ;  but  in  presence  of  antimony  this  Ct  is  surrounded  by 
another,  white  one,  of  antimonious  acid.  The  oxide  of  lead  Ct 
appears,  moreover,  darker  than  usual,  resembling  that  of  bismuth, 
owing  probably  to  the  formation  of  antimonate  of  lead.  If  this 
Ct  is  scraped  off  from  the  Ch  and  treated  with  S  Ph  as  mentioned 
§  59,  in  the  case  of  bismuth,  the  bead,  on  cooling,  assumes  a  black 
color,  whereby,  in  absence  of  bismuth,  the  presence  of  antimony 
is  proved.  A  very  small  quantity  of  antimony  can  by  this  method 
not  be  found  out  with  certainty,  since,  by  keeping  up  the  blast  for 
some  time,  the  sulphide  of  sodium  begins  to  vaporize  and  to  coat 
the  Ch  with  a  ring  of  sulphate  of  soda  (v.  §  30). 

§  88.  When  sulphide  of  lead  is  associated  with  a  considerable 
quantity  of  sulphide  of  copper  [No.  89],  the  metallic  globule, 
obtained  by  the  process  of  reduction,  does  not  betray,  by  its  phys 
ical  properties,  the  presence  of  lead.  But  if  the  alloy  is  removed 
from  the  flux  and  played  upon  with  a  powerful  O  Fl,  the  greater 
part  of  the  lead  will  be  volatilized  and  deposit  a  Ct. 

Litliia. 

§  89.  To  detect  lithia  in  silicates  which  contain  only  little  of  it, 
proceed  as  follows  :  The  substance  [No.  67]  is  reduced  to  a  fine 
powder  and  mixed  \vith  about  2  parts  of  a  mixture  of  1  part  of 
fluor-spar  with  1^  parts  of  bisulphate  of  potassa;  a  few  drops  of 


BLOW-PIPE    ANALYSIS.  53 

water  are  added  and  the  whole  kneaded  into  a  paste.  The  mass  is 
fused  with  the  blue  cone  of  the  flame  into  the  hook  of  a  platinum 
wire.  If  lithia  is  present  the  outer  flame  will  appear  red.  The 
color  is  not  very  intense,  and  verging  into  violet.  The  presence 
of  potassa  does  not  prevent  the  reaction,  but  makes  the  flame 
appear  still  more  violet ;  soda  makes  the  reaction  uncertain. 

Manganese. 

The  reactions  of  manganese,  see  Table  II,  13. 

§  90.  The  presence  of  manganese  in  any  compound  substance  is 
readily  detected  by  mixing  the  pulverized  assay  [No.  66  or  No.  84] 
with  about  2  or  3  parts  of  Sd,  and  fusing  it  by  means  of  the  0  Fl 
on  platinum  foil.  Manganate  of  soda  is  formed,  which,  while  hot, 
is  green  and  transparent,  and,  on  cooling,  turns  bluish-green  and 
opaque.  The  reaction  is  very  distinct  when 'as  much  as  one-tenth 
per  cent,  of  manganese  is  present.  But  even  the  slightest  trace 
may  be  detected  when,  instead  of  Sd,  a  mixture  of  1  part  of  nitre 
with  2  parts  of  Sd  is  used.  Chromium  does  not  prevent  the 
reaction,  merely  changing  the  color  to  yellowish-green.  It  is  only 
in  presence  of  silica  and  cobalt  that  this  test  is  not  available,  since 
at  a  high  temperature  the  silica  unites  with  the  soda  to  silicate  of 
soda,  which,  in  dissolving  the  oxide  of  cobalt,  produces  a  blue  glass, 
and  thus  interferes  with  the  manganese  color. 

Mercury. 

The  reactions  of  mercury  and  its  compounds,  see  §§  11,  IT,  and 
Table  II,  14. 

§  91.  Mercury  is  detected  in  amalgams  [No.  47]  by  the  sublimate 
of  metallic  mercury  which  they  yield,  when  heated  in  a  glass  tube 
closed  at  one  end. 

When  in  combination  with  sulphur  [No.  81],  chlorine  [No.  39], 
iodine  or  ox-acids,  the  substance  is  previously  mixed  with  some 
anhydrous  Sd  or  some  neutral  oxalate  of  potassa.  The  acids,  <fec., 
are  retained  by  the  soda,  and  mercury  sublimes. 

If  the  quantity  of  mercury  is  so  small,  that  the  nature  of  the 

sublimate  cannot  with  certainty  be  ascertained,  the  experiment  has 

to  be  repeated,  a  piece  of  iron  wire  around  which  a  gold-leaf  has 

been  wrapped  being  at  the  same  time  introduced  into  the  tube  and 

5* 


54  ELDERIIORST'S  MANUAL  OF 

held  close  above  the  assay.     The  gold-leaf  will  turn  white  if  ever 
so  little  mercury  be  present. 

Nickel. 

The  reactions  of  nickel,  see  Table  II,  16. 

§  92.  To  detect  nickel  in  metallic  compounds  which  are  fusible 
before  the  Blp,  the  assay  is  treated  with  Bx  on  Ch  in  the  R  Fl ; 
iron,  cobalt,  &c.,  enter  into  the  flux  and  may  be  detected  as  shown 
§  G9,  while  the  metals  whose  oxides  are  easily  reduced  remain 
behind.  This  operation  is  repeated  until  the  glass  appears  no 
longer  colored.  The  remaining  globule  is  treated  with  S  Ph  in  the 
0  Fl.  We  now  obtain  either  the  pure  color  of  nickel,  or  that  of 
nickel  mixed  with  copper  (v.  §  72);  in  this  case  it  is  treated  on  Ch 
with  tin,  whereby  the  presence  of  copper  may  be  ascertained. 
Bismuth  or  antimony  prevents  the  reaction  for  .copper,  the  bead 
turning  black,  instead  of  red.  Such  compounds  must,  previous  to 
their  treatment  with  fluxes,  be  heated,  on  Ch  in  R  Fl  until  all 
volatile  substances  are  driven  off  [No.  82]. 

In  arsenides  and  sulphides  nickel  is  detected  by  the  methods 
given  for  cobalt  under  the  same  circumstances  (v.  §  70). 

Nitric  acid. 

§  93.  The  perfectly  dry  substance  [No.  23]  is  heated  in  a  matrass 
with  some  bisulphate  of  potassa ;  orange-yellow  vapors  of  nitrous 
acid  are  emitted,  even  if  but  a  small  quantity  of  a  nitrate  is  present. 

Phosphoric  acid. 

§  94.  A  very  minute  quantity  of  phosphoric  acid  may  be  detected 
by  pulverizing  the  substance  [No.  14],  adding  a  drop  of  concen 
trated  sulphuric  acid,  fastening  the  paste  into  the  hook  of  a  plati 
num  wire,  and  playing  upon  it  with  the  blue  cone  of  the  flame  ; 
the  outer  flame  will  assume  a  bluish-green  color  (v.  §  35). 

Certain  azotizcd  compounds,  as  nitric  acid,  nitrate  of  ammonia, 
chloride  of  ammonium,  &c.,  when  fastened  into  the  hook  of  a  plati 
num  wire  and  touched  with  the  cone  of  the  blue  flame,  impart  to 
the  outer  flame  a  bluish-green  color,  resembling  that  caused  by 
phosphoric  acid. 

§  95.  In  a  substance,  containing  not  less  than  about  5  per  cent, 
of  phosphoric  acid,  the  presence  of  the  latter  may  be  shown  by  dis- 


BLOW-PIPE    ANALYSIS.  55 

solving  the  assay  [Xo.  68]  on  Ch  in  boracic  acid  and  forcing  into 
the  glass,  when  a  good  fusion  is  effected,  a  piece  of  fine  steel  wire  ; 
a  good  R  Fl  is  then  given.  The  iron  is  oxidized  at  the  expense  of 
the  phosphoric  acid,  causing  the  formation  of  a  borate  of  the  oxide 
of  iron  and  phosphide  of  iron,  which  fuses  at  a  sufficiently  high 
temperature.  The  bead  is  then  taken  from  the  Ch,  enveloped  in  a 
piece  of  paper,  and  struck  lightly  with  a  hammer,  by  which  means 
the  phosphide  of  iron  is  separated  from  the  surrounding  flux.  It 
exists  as  a  metallic-looking  button,  attractable  by  the  magnet,  fran 
gible  on  the  anvil,  the  fracture  having  the  color  of  iron.  If  the  sub 
stance  under  assay  contained  no  phosphoric  acid,  the  iron  wire  will 
keep  its  form  and  metallic  lustre,  excepting  at  the  ends,  where  it 
will  be  oxidated  and  burnt.  The  substance  to  be  assayed  ought  not 
to  contain  sulphuric  acid,  arsenic  acid,  or  any  metallic  oxides  re 
ducible  by  iron. 

Phosphate  of  lead  exhibits  the  peculiarity  of  crystallizing  on 
cooling  after  having  been  fused  on  Ch  ;  the  crystals  have  frequently 
large  facets  of  a  pearly  lustre. 

Potassa. 

§  97.  The  violet  color  of  the  flame  is  sufficiently  characteristic  for 
potassa  (v.  §  33).  But  being  altogether  prevented  or,  at  least,  made 
very  indistinct  by  the  addition  of  a  few  per  cent,  of  soda  or  lithia, 
it  can  only  in  a  very  few  cases  be  made  use  of.  For  the  detection 
of  potassa  in  silicates  it  is  almost  entirely  unavailable,  because  these 
compounds  almost  always  contain  some  soda. 

§  98.  If  the  base  of  a  compound  consists  essentially  of  potassa, 
the  following  method  may  be  advantageously  employed  for  its  de 
tection  :  Some  Bx,  to  which  a  little  boracic  acid  has  been  added,  is 
melted  into  the  hook  of  a  platinum  wire  and  so  much  protoxide  of 
nickel  added  that  the  glass  on  cooling  shows  a  distinct  brownish 
color.  A  small  piece  of  the  substance  under  examination  [No.  15] 
is  made  to  adhere  to  the  glass  and  the  whole  fused  together  with 
the  0  Fl.  If  the  assay-piece  contained  no  potassa,  the  color  of  the 
glass,  after  perfect  cooling,  will  have  remained  unchanged ;  but  if 
potassa  was  present  in  sufficient  quantity,  the  glass  will  appear 
bluish. 


56  ELDERIIORST'S  MANUAL  OF 

Selenium. 

§  99.  The  reactions  of  selenium  arc  very  characteristic.  In  non 
volatile  compounds,  which  do  not  give  the  red  sublimate  mentioned 
§  11,  the  selenium  is  detected  by  heating  a  small  piece  of  the  sub 
stance  [No.  87]  on  Ch  in  0  Fl,  when  the  peculiar  odor  is  evolved; 
if  much  selenium  is  present,  a  Ct  is  deposited,  v.  §  28.  Selenites 
and  selenates  are  treated  on  Ch  with  Sd  in  R  Fl,  when  a  reduction 
takes  place  and  the  selenium  vaporizes  with  the  characteristic  odor. 

Silica. 

§  100.  Pure  silica  [No.  54],  when  treated  with  Bx  on  platinum 
wire,  dissolves  slowly  to  a  transparent  glass  which  fuses  with  diffi 
culty.  Treated  with  S  Ph  in  the  same  manner,  only  a  small  quan 
tity  is  dissolved,  the  rest  floating  in  the  liquid  bead  as  a  semi- 
transparent  mass.  The  behavior  to  Sd  sec  §  39.  With  a  little 
So  Co  it  assumes  a  pale  bluish  color  which,  on  addition  of  a  large 
quantity  of  the  reagent,  turns  dark-gray  or  black;  very  thin  splinters 
may  be  fussed  by  a  great  heat  to  a  reddish-blue  glass. 

§  101.  Silicates  [No.  61],  when  treated  with  S  Ph  on  platinum 
wire,  are  decomposed;  the  bases  unite  with  the  free  phosphoric  acid 
to  a  transparent  glass  in  which  the  silica  may  be  seen  floating  as  a 
gelatinous  cloudy  mass.  The  bead  ought  to  be  carefully  observed 
while  hot,  since  many  silicates  form  a  glass  which  on  cooling 
opalizcs  or  becomes  opaque,  when,  of  course,  the  phenomenon  can 
no  longer  be  seen.  The  experiment  is  best  performed  with  a  small 
splinter  of  the  substance  under  examination,  and  only  when  this 
does  not  appear  to  be  affected  by  the  flux,  the  finely  pulverized  sub 
stance  should  be  used.  If  but  a  very  small  quantity  of  silica  is 
present,  the  glass  will  appear  perfectly  transparent.  Its  presence  in 
this  case  cannot  be  detected  by  means  of  the  Blp. 

§  102.  Silicates  containing  at  least  so  much  silica  that  the  quan 
tity  of  oxygen  in  the  acid  is  twice  that  of  the  oxygen  in  the  base, 
dissolve,  when  treated  with  Sd  on  Ch,  with  effervescence  to  a 
transparent  glass  which  remains  so  when  cold.  When  less  silica 
is  present  decomposition  also  takes  place,  but  the  glass  turns  opaque 
on  cooling,  the  amount  of  silicate  of  soda  which  is  formed  not  being 
sufficient  to  dissolve  the  eliminated  bases. 


BLOW-PIPE    ANALYSIS.  57 

Silver. 

The  reactions  of  silver,  see  §  27,  and  Table  II,  20. 

§  103.  When  in  combination  with  metals  which  are  volatile  at  a 
high  temperature,  ex.  gr.  bismuth,  lead,  zinc,  antimony,  the  substance 
is  heated  alone  on  Ch,  when,  after  evaporation  of  the  foreign  metals,  i 
a  button  of  pure  silver  remains  behind  and  a  feeble  reddish  Ct  is 
deposited  on  the  Ch.  If  associated  with  much  lead  or  bismuth, 
these  metals  are  best  removed  by  cupellation,  a  process  which  is 
executed  in  the  following  manner:  Finely  pulverized  bone-ash  is 
mixed  with  a  minute  quantity  of  soda  and  made  with  a  little  water 
into  a  stiff  paste;  a  hole  is  now  bored  into  the  Ch,  filled  with  the 
paste,  and  its  surface  smoothed  and  made  slightly  concave  by 
pressing  on  it  with  the  pestle  of  the  little  agate  mortar.  The  mass 
is  then  dried  by  the  flame  of  a  common  spirit  lamp.  On  this  little 
cupel  the  assay  [No.  51]  is  placed  and  so  long  heated  with  the  O 
PI  until  the  whole  of  the  lead  or  bismuth  is  oxidized  and  absorbed 
by  the  cupel.  The  silver  or,  if  gold  is  present,  the  alloy  of  silver 
and  gold  remains  as  a  bright  metallic  button  on  the  cupel. 

§  104.  When  combined  with  metals  which  are  not  volatile,  but 
which  are  easier  oxidized  than  silver,  the  presence  of  this  metal 
may  in  some  cases  be  detected  by  simply  treating  the  alloy  with 
Bx  or  S  Ph  on  Ch.  Copper,  nickel,  cobalt,  &c.,  become  oxidized 
and  their  oxides  dissolved  by  the  flux,  while  silver  remains  behind 
\vith  a  bright  metallic  surface.  But  when  these  metals  are  present 
to  a  considerable  extent,  another  course  has  to  be  pursued,  a  course 
which  may  always  be  taken  when  a  substance  is  to  be  assayed  for 
silver,  or  silver  and  gold. 

§  105.  The  assay-piece  [No.  86]  is  reduced  to  a  fine  powder, 
mixed  with  vitrified  Bx  and  metallic  lead  (the  quantities  of  which 
altogether  depend  upon  the  nature- of  the  substance,  and  for  which, 
therefore,  no  general  rule  can  be  given),  and  the  mass  placed  in  a 
cylindrical  hole  of  the  Ch.  A  powerful  R  Fl  is  given  until  the 
metals  have  united  to  a  button,  and  the  slag  appears  free  from 
metallic  globules.  The  flame  is  now  converted  into  a  0  Fl  and 
directed  principally  upon  the  button.  Sulphur,  arsenic,  antimony, 
and  other  very  volatile  substances,  arc  volatilized ;  iron,  tin,  cobalt, 


58  ELDERIIORST'S  MANUAL  OF 

and  a  little  copper  and  nickel  become  oxidized  and  are  absorbed  by 
the  flux;  silver  and  gold  and  the  greater  part  of  copper  and  nickel 
remain  with  the  lead  (and  bismuth,  if  present).  When  all  volatile 
substances  are  driven  off,  the  lead  begins  to  become  oxidized,  and 
the  button  assumes  a  rotary  motion;  at  this  period  the  blast  is  dis 
continued,  the  assay  is  allowed  to  cool,  and  when  perfectly  cold  the 
lead  button  is  separated  from  the  glass  by  some  slight  strokes  with 
a  hammer.  It  is  now  placed  on  a  cupel  of  bone-ash  and  treated 
with  the  0  Fl  until  it  again  assumes  a  rotatory  motion.  If  much 
copper  or  nickel  is  present,  the  globule  becomes  covered  with  a 
thick  infusible  crust,  which  prevents  the  aimcd-at  oxidation;  in  this 
case  another  small  piece  of  pure  lead  has  to  be  added.  The  blast 
is  kept  up  until  the  whole  of  the  lead  and  other  foreign  metals, 
viz.,  copper  and  nickel,  are  oxidized ;  this  is  indicated  by  the  ces 
sation  of  the  rotatory  movement,  if  only  little  silver  is  present,  or 
by  the  appearance  of  all  the  tints  of  the  rainbow  over  the  whole 
surface  of  the  button,  if  the  ore  was  very  rich  in  silver;  after  a  few 
moments  it  takes  the  look  of  pure  silver.  The  oxides  of  lead, 
copper,  &c.,  are  absorbed  by  the  bone-ash,  and  pure  silver,  or  an 
alloy  of  silver  with  other  noble  metals,  remains  behind;  the  button 
may  be  tested  for  gold,  &c.,  after  the  method  given  in  §  79. 

Sulphur. 

§  100.  The  presence  of  sulphur  in  sulphides  may  in  many  cases 
be  detected  by  heating  in  a  glass  tube  (v.  §§  11,  14),  or  on  Ch  with 
the  0  Fl. 

§  10*7.  A  very  delicate  test  for  the  presence  of  sulphur,  in  what 
ever  combination  it  may  be  contained  in  the  substance,  and  which 
possesses  moreover  the  advantage  over  all  other  methods  of  being- 
very  easily  performed,  is  to  mix  the  pulverized  assay  [No.  4]  with 
some  pure  Sd  or,  better  still,  with  a  mixture  of  two  parts  of  Sd 
and  1  of  Bx,  and  to  treat  it  on  Ch  with  the  R  Fl.  The  fused  mass  is 
removed  from  the  Ch,  powdered,  the  powder  placed  on  a  silver  foil 
or  a  bright  silver  coin,  and  a  drop  of  water  added.  If  the  substance 
under  examination  contained  any  sulphur,  a  black  spot  will  be 
formed  on  the  silver  foil,  owing  to  the  formation  of  sulphide  of 
silver  from  the  decomposition  of  the  sulphide  of  sodium,  which,  iii 


BLOW-PIPE    ANALYSIS.  59 

its  turn,  resulted  from  the  decomposition  of  the  sulphide  or  sul 
phate,  or  other  sulphur-compound  of  the  assay-piece,  under  the 
influence  of  Sd,  Ch,  and  a  high  temperature.  Selenium  shows  the 
same  reaction ;  it  is  readily  recognized  by  the  peculiar  odor  which 
it  emits  when  heated  on  Ch  alone. 

§  108.  To  decide  whether  the  reaction  obtained  in  the  experiment 
was  owing  to  the  presence  of  a  sulphide  or  to  that  of  a  sulphate, 
the  finely-pulverized  substance  [No.  76]  is  fused  in  a  small  platinum 
spoon  with  some  hydrate  of  potassa.  The  spoon  with  the  contents 
is  then  placed  into  a  vessel  containing  some  water,  and  a  piece  of 
silver  foil  inserted  into  the  liquid.  If  the  silver  remains  perfectly 
bright,  a  sulphate  was  present,  if  it  turns  black,  a  sulphide.  The 
absence  of  substances  which  might  exercise  a  reducing  influence  is 
required. 

Tellurium. 

§  109.  The  presence  of  tellurium  in  mineral  substances  is  detected 
by  the  tests  given  §§  11,  18,  29.  In  presence  of  lead  or  bismuth 
the  reactions  in  the  open  tubes  and  on  Ch  are  not  quite  pure.  In 
this  case  we  may  subject  the  assay  to  the  following  treatment:  The 
substance  is  mixed  with  some  Sd  and  charcoal-powder,  the  mixture 
introduced  into  a  glass  tube  closed  at  one  end,  and  heated  to  fusion ; 
after  cooling,  a  few  drops  of  hot  water  are  poured  into  the  tube;  if 
tellurium  was  present,  telluride  of  sodium  has  been  formed,  which 
dissolves  in  hot  water  with  a  purplish-red  color.  This  test  is  ap 
plicable  to  show  the  presence  of  tellurium  in  a  great  many  com 
pounds,  even  in  such  where  it  occurs  in  the  oxidized  state. 

Tin. 

The  reactions  of  tin  and  its  compounds,  see  §§  12,  26,  45,  and 
Table  II,  22. 

§  110.  The  presence  of  tin  is  indicated  by  its  Ct  when  the  sub 
stance  [No.  13],  alone  or  mixed  with  Sd,  is  exposed  to  the  R  Fl 
on  Ch. 

When  the  substance  under  examination  is  an  alloy,  a  little  Bx 
is  conveniently  added,  which  absorbs  the  oxide  of  tin  in  the  measure 
as  it  is  formed,  and  allows  the  presence  of  those  metals  which  are 
more  volatile,  ex.  gr.  antimony,  lead,  bismuth,  to  be  recognized  by 


60  ELDERIIORST'S  MANUAL  OF 

their  coatings.  Arsenic  is  detected  by  its  odor,  arid  iron  by  the 
color  which  the  Bx  bead  assumes  when  re-fused  on  platinum  wire  in 
the  0  Fl. 

To  detect  copper  in  tin  or  its  alloy,  the  assay  [No.  52]  is  fused 
with  a  flux  consisting  of  100  parts  of  Sd,  50  of  vitrified  Bx,  and  30 
of  silica.  The  flame  is  so  directed  that  the  metallic  globule  assumes  ' 
a  rotatory  motion.  When  in  this  state  the  glass  is  kept  covered, 
as  much  as  possible,  with  the  0  Fl,  care  being  taken  that  the  glo 
bule  is  at  one  side  in  contact  with  the  glass,  and  at  the  other  with 
the  Ch.  The  tin  becomes  oxidized  and  the  oxide,  in  the  measure 
as  it  is  formed,  absorbed  by  the  flux ;  the  remaining  button  is  copper, 
pure  or  with  a  small  quantity  of  tin,  and  may  be  readily  tested  with 
the  usual  fluxes. 

Titanium. 

§  111.  Titanic  acid,  when  forming  the  principal  constituent  of 
any  mineral  substance,  is  easily  detected  by  its  behavior  with  the 
fluxes,  v.  Table  II,  23 ;  but  when  in  combination  with  bases  these 
reactions  are  not  always  clearly  perceptible,  being  frequently  sup 
pressed  by  the  predominating  reaction  of  the  base.  In  such  cases 
we  may  subject  the  assay  to  the  following  treatment,  by  which 
even  very  small  quantities  of  titanic  acid  will  become  apparent :  the 
substance  [No.  65]  is  reduced  to  a  very  fine  pow^der,  mixed  with 
from  6  to  8  parts  of  bisulphate  of  potassa,  and  fused  in  a  platinum 
spoon  at  a  low  red-heat ;  the  fused  mass  is  dissolved  in  a  porcelain 
vessel  in  the  smallest  possible  quantity  of  water,  aided  by  heat. 
There  remains  an  insoluble  residue  which  is  allowed  to  settle ;  the 
clear  liquid  is  poured  oft'  into  a  larger  vessel,  mixed  with  a  few 
drops  of  nitric  acid  and  at  least  six  volumes  of  water,  and  heated 
to  ebullition.  If  the  substance  under  examination  contained  any 
titanium,  a  white  precipitate  of  titanic  acid  forms  on  boiling.  The 
precipitate  is  collected  on  a  filter,  washed  with  water,  acidulated 
with  nitric  acid,  and  tested  with  S  Pb. 

Uranium. 

§  112.  The  presence  of  this  metal  is  easily  recognized,  in  sub 
stances  which  contain  no  other  coloring  constituents,  by  the  reac 
tions  given  Table  II,  25  ;  the  most  characteristic  test  is  that  with 


BLOW-PIPE    ANALYSIS.  61 

S  Ph.  In  presence  of  much  iron  this  reaction  becomes  indistinct ; 
we  may  then  operate  in  the  following  manner  :  the  finely-pulverized 
substance  [No.  70]  is  fused  with  bisulphate  of  potassa,  the  fused 
mass  dissolved  in  water,  mixed  with  carbonate  of  ammonia  in  excess, 
the  liquid  separated  from  the  precipitate  by  nitration,  and  the  nitrate 
heated  to  ebullition.  If  any  uranium  was  present,  a  yellow  pre 
cipitate  is  thrown  down,  which  gives  with  the  fluxes  the  pure  re 
actions  of  uranium. 

Zinc. 

The  reactions  for  zinc  and  its  compounds,  see  §§  12,  25,  45,  and 
Table  II,  27. 

§  113.  A  small  amount  of  zinc,  when  associated  with  consider 
able  quantities  of  lead,  or  bismuth,  or  antimony,  or  tin,  cannot  with 
certainty  be  ascertained  by  means  of  the  Blp. 

If  the  substance  under  examination  contains  the  zinc  as  oxide 
[No.  36],  or  but  a  small  quantity  of  sulphide,  it  is  mixed  with  Sd 
and  treated  on  Ch  in  R  Fl.  Substances  consisting  essentially  of 
sulphide  of  zinc  may  be  thus  treated  without  the  addition  of  Sd, 
and  such  as  contain,  beside  oxide  of  zinc,  other  metallic  oxides,  are 
conveniently  mixed  with  some  Sd  to  which  about  one-half  of  its 
weight  of  Bx  has  been  added.  A  ring  of  oxide  of  zinc  is  deposited 
on  the  Ch.  When  lead  is  present  [No.  51]  the  Ct  is  frequently 
not  pure,  being  mixed  up  with  the  Ct  of  lead.  In  this  case  it  is 
moistened  with  some  So  Co  and  heated  again  with  the  0  Fl.  The 
oxide  of  lead  is  reduced  by  the  red-hot  Ch  and  volatilized,  while 
the  oxide  of  zinc  remains  behind  with  a  green  color  (v.  §  45). 
6 


62  ELDERIIORST'S  MANUAL  OF 


FOURTH    CHAPTER. 

CHARACTERISTICS    OF    THE    MOST    IMPORTANT    ORES;    THEIR    BE- 
JIAVIOR   BEFORE   THE   BLOW-PIPE,  AND    TO   SOLVENTS. 

§  114.  OF  the  physical  properties  of  the  minerals  which  are  treated 
of  in  this  chapter,  only  those  are  enumerated  which  serve  best  to 
discriminate  the  different  ores  from  each  other.  For  a  more  detailed 
description  I  must  refer  to  Dana's  and  other  works  on  mineralogy. 
Among  the  distinguishing  characters  of  minerals,  their  hardness 
and  specific  gravity  stand  foremost.  The  latter  cannot  be  ascer 
tained  without  a  good  balance,  and  will,  for  this  reason,  be  of  much 
less  use  to  the  practical  man  than  the  determination  of  hardness,  an 
operation  which  may  be  performed  in  a  few  moments.  A  set  of 
minerals,  representing  the  scale  of  hardness,  being  not  always  at 
hand,  it  will  be  useful  to  give  a  scries  of  substitutes  for  them,  as 
arranged  by  Mr.  Chapman: 

1.  Yields  easily  to  the  nail. 

2.  Yields  with  difficulty  to  the  nail,  or  merely  receives  an  impres 
sion  from  it.     Does  not  scratch  a  copper  coin. 

3.  Scratches  a  copper  coin ;  but  is  also  scratched  by  it,  being  of 
about  the  same  degree  of  hardness. 

4.  Not  scratched  by  a  copper  coin;  does  not  scratch  glass. 

5.  Scratches  glass,  though  rather  with  difficulty,  leaving  its  pow 
der  on  it.     Yields  readily  to  the  knife. 

(>.  Scratches  glass  easily.     Yields  writh  difficulty  to  the  knife. 

7.  Does  not  yield  to  the  knife.     Yields  to  the  edge  of  a  file, 
though  with  difficulty. 

8.  9.  10.  Harder  than  flint. 

The  scale  of  hardness,  as  introduced  by  Mohs,  and  enlarged  by 
Breithaupt,  is  as  follows: 

1.  Talc;  common  laminated  light-green  variety. 

2.  Gypsum ;  a  crystalline  variety. 


BLOW-PIPE    ANALYSIS.  63 

2.5.  Foliated  Mica. 

3.  Calcareous  Spar;  transparent  variety. 

4.  Fluor  Spar;  crystalline  variety. 

5.  Apatite ;  transparent  variety. 
5.5.  Scapolite;  crystalline  variety. 

6.  Orthoclase;  white  cleavable  variety. 

7.  Quartz;  transparent. 

8.  Topaz;  transparent. 

9.  Sapphire;  cleavable  varieties. 

10.  Diamond. 

To  test  the  hardness  of  a  mineral  we  may  proceed  in  two  differ 
ent  manners:  firstly,  by  attempting  to  scratch  it  writh  the  minerals 
enumerated  in  the  scale,  successively,  or,  secondly,  by  abrasion  with 
a  file.  If  the  file  abrades  the  mineral  under  trial  with  the  same 
ease  as  No.  4,  and  produces  an  equal  depth  of  abrasion  with  the 
same  force,  its  hardness  is  said  to  be  4.  If  with  more  facility  than 
4,  but  less  than  5,  the  hardness  may  be  4£  or  4J.  Several  succes 
sive  trials  should  be  made  to  obtain  certain  results;  and,  when 
practicable,  both  methods  should  be  employed. 

ORES  OF  ANTIMONY. 

Gray  Antimony  [Stibnite]. 

§  115.  Sb  S3.  H=2.  G=4.5.  Of  lead-gray  color  and  metallic 
lustre.  Usually  of  columnar  structure,  consisting  of  a  vast  number 
of  needle-shaped  crystals,  sometimes  side  by  side,  sometimes  diver 
gent.  Very  brittle. 

It  fuses  readily  in  the  flame  of  a  candle.  In  a  matrass,  some 
times  yields  a  slight  sublimate  of  sulphur  ;  on  increasing  the  heat 
by  application  of  the  Blp  flame,  a  sublimate  is  produced  wrhich 
after  cooling  is  brownish-red,  and  which  consists  of  a  mixture  of 
tersulphide  of  antimony  with  antimonious  acid.  In  an  open  glass 
tube,  emits  sulphurous  acid  and  antinionial  fumes.  On  Ch  it  is 
volatilized,  covering  the  Ch  with  oxide  of  antimony,  which,  when 
touched  with  the  R  Fl,  disappears  with  a  pale  greenish-blue  tinge. 

When  pure,  wholly  soluble  in  heated  hydrochloric  acid  with 
evolution  of  sulphuretted  hydrogen ;  usually  a  residue  of  chloride 


4>4  ELDERIIORST'S  MANUAL  OF 

of  lead  is  left.  Partly  decomposed  by  caustic  potassa ;  the  solu 
tion,  when  mixed  with  an  acid,  affords  a  yellowish-red  precipitate. 

Berthierite. 

§  116.  Composition  variable,  sometimes  FeS-f-SbS3.  11=2—3. 
0=4 — 4.3.  Metallic  lustre,  less  splendent  than  gray  antimony; 
color  dark  steel-gray. 

Heated  in  a  matrass,  fuses  and  yields  a  slight  sublimate  of  sul 
phur  ;  on  application  of  a  strong  heat,  a  black  sublimate  of  sul 
phide  of  antimony  is  formed,  which,  on  cooling,  becomes  brownish- 
red.  In  an  open  glass  tube  it  behaves  like  the  preceding  ore.  In 
Oh,  fuses  easily  and  coats  the  charcoal  with  oxide  of  antimony ; 
there  remains,  finally,  a  black  slag,  which  is  attracted  by  the  magnet 
and  gives  with  fluxes  the  iron  reaction. 

Soluble  in  hydrochloric  acid. 

Red  Antimony  [Kermesite]. 

§117.  2SbSs-fSb03.  11=1—1.5.  0=4.5—4.6.  Usually  in 
tufts  of  capillary  crystals  of  cherry-red  color. 

In  a  matrass,  fuses  readily  and  yields  a  slight  yellowish-red  subli 
mate  ;  with  strong  heat,  boils  and  gives  a  black  sublimate  which, 
when  cold,  is  brownish-red.  In  an  open  tube  and  on  Ch,  behaves 
like  gray  antimony. 

It  dissolves  in  hydrochloric  acid  with  evolution  of  sulphuretted 
hydrogen.  The  powdered  mineral,  when  treated  with  caustic 
potassa,  assumes  an  ochre-yellow  color  and  dissolves  completely. 

ORES  OF  ARSENIC. 

Native  Arsenic. 

§  118.  As,  with  traces  of  Sb,  Ag,  Fe,  Co,  and  Ni.  11=3.5. 
(3_5  9  Of  metallic  lustre  and  tin-white  color,  tarnishing  on 
exposure  to  air  to  dark-gray. 

Heated  in  a  matrass,  sublimes  ;  on  Ch,  behaves  like  pure  arsenic. 
In  both  cases,  sometimes,  a  residue  is  left,  which,  when  treated 
with  fluxes,  exhibits  the  reactions  of  iron,  cobalt,  and  nickel. 
(See  §  83.) 

Realgar. 

§  119.  As  S2.  11=1.5—2.  0  =  3.4—3.6.  Usually  of  bright-red, 
sometimes  of  orange-yellow  color,  and  resinous  lustre.  Sectile. 


BLOW-PIPE    ANALYSIS.  65 

In  a  matrass,  fuses,  boils,  and  finally  sublimes;  the  sublimate, 
after  cooling,  is  red  and  transparent.  In  an  open  glass  tube,  when 
carefully  heated,  yields  a  sublimate  of  arsenous  acid,  sulphurous 
acid  escaping.  On  Ch,  fuses  readily  and  burns  with  a  yellowish- 
white  flame,  emitting  grayish-white  fumes  which  possess  the 
peculiar  alliaceous  odor.  Subjected  to  the  treatment  described 
§  55,  a  sublimate  of  metallic  arsenic  is  obtained. 

Not  easily  affected  by  acids ;  but  aqua  regia  dissolves  it  with 
continued  digestion,  part  of  the  sulphur  being  precipitated.  A 
heated  solution  of  caustic  potassa  decomposes  it,  leaving  a  brown 
ish-black  powder  (As6S)  undissolved. 

Orpiment. 

§  120.  AsS3.  11=1.5—2.  G=3.4.  A  foliaceous  mineral  of 
lemon-yellow  color,  and  resinous  or  pearly  lustre.  Sectile. 

Before  the  Blp,  behaves  like  the  preceding,  with  this  difference, 
that  the  sublimate,  after  cooling,  is  dark  yellow  and  transparent. 

Soluble  in  aqua  regia,  caustic  potassa,  and  ammonia. 

White  Arsenic  [Arsenolite]. 

§  121.  AsO3.  11=1.5.  G=3.6.  Occurs  usually  in  minute  capil 
lary  crystals  of  a  white  color,  and  vitreous  or  silky  lustre. 

Before  the  Blp  it  behaves  like  pure  arsenous  acid  (v.  §§  9,  15> 
Table  II,  2). 

Slightly  soluble  in  hot  water;  more  so  in  water  acidulated  with 
hydrochloric  acid. 

ORES  OP  BISMUTH. 

Native  Bismuth. 

§  122.  Bi;  H=2— 2.5.  G=9.7.  Color  silver-white,  tinged  with 
red.  Lustre  metallic.  Brittle  when  cold;  but,  when  hot,  may  be 
laminated.  Occurs  foliated,  granular,  and  arborescent ;  occasionally 
crystallized. 

Before  the  Blp  it  behaves  like  pure  bismuth  (v.  §§  17,  22). 

Readily  dissolved  by  nitric  acid ;  the  solution  is  precipitated  by 
water. 

Telluric  Bismuth  [Tetradymite]. 

§  123.  Bi  and  Te  in  variable  proportions.     n=1.5— 2.     G=7.3 
6*  E 


66  ELDERHORST'S  MANUAL  OP 

—8.4.  Of  pale  steel-gray  color,  and  high  metallic  lustre.  Occurs 
usually  in  tabular  crystals,  or  foliated  masses;  the  laminae  are 
elastic.  It  soils  paper. 

In  an  open  glass  tube  it  fuses  readily,  emitting  a  white  smoke 
which  partly  condenses,  coating  the  tube  near  the  assay-piece  with 
a  white  powder,  intermixed  with  red  spots ;  on  directing  the  flame 
on  this  Ct,  it  fuses  to  colorless  drops  (TeO2),  while  the  red  sub 
limate  (Se)  disappears.  On  Ch,  fuses  instantly  to  a  metallic  globule 
which,  when  touched  with  the  inner  flame,  imparts  a  bluish-green 
color  to  the  outer  one,  sometimes  gives  out  selenium  vapors,  and 
deposits,  close  to  the  assay-piece,  a  dark  orange  Ct,  surrounded  at 
a  greater  distance  by  a  white  Ct. 

Soluble  in  nitric  acid. 

Bismutite. 

§  124.  3(Bi03.C02-fHO)  +  Bi03.HO.  11=4— 4.5.  G=G.9.  Usu 
ally  of  a  white  or  light  greenish  color,  and  vitreous  lustre;  in  acicu- 
lar  crystallizations. 

In  a  matrass,  decrepitates,  yields  a  little  water,  and  turns  gray. 
On  Ch,  fuses  very  readily  and  is  reduced,  with  effervescence,  to  a 
metallic  globule,  covering  the  Ch  with  a  Ct  of  oxide  of  bismuth. 
If  the  blast  is  kept  up  for  some  time  the  whole  of  the  bismuth  is 
volatilized  and  there  remains  a  scoriaceous  mass  which,  in  the  R 
Fl,  may  be  fused  to  a  globule,  and  which  with  fluxes  gives  the 
indications  of  copper  and  iron.  With  Sd  it  usually  gives  the  sul 
phur  reaction  (§  107). 

Dissolves  in  hydrochloric  acid  with  effervescence;  the  solution 
has  a  yellow  color. 

Bismutliine. 

§  125.  BiS3.  H=2— 2.5.  G=  6.4— 6.55.     In  acicular  crystals  or. 
massive;  of  metallic  lustre,  and  lead-gray  color,  with  a  yellowish 
or  iridescent  tarnish. 

In  a  matrass,  fuses  and  yields  a  slight  sublimate  of  sulphur- 
Carefully  heated  in  an  open  tube,  it  fuses  and  yields  sulphurous 
acid  and  a  coat  of  sulphate  of  bismuth;  the  latter  may  be  fused,  by 
application  of  the  Blp  flame,  to  brown  drops  which,  when  cold, 
appear  yellow  and  opaque.  On  Ch,  fuses  and  boils,  throwing  out 


BLOW-PIPE    ANALYSIS.  67 

small  drops  in  a  state  of  incandescence,  and  deposits  a  Ct  of  oxide 
of  bismuth. 

Soluble  in  nitric  acid  with  deposition  of  sulphur.  The  solution 
gives  a  white  precipitate  with  water. 

Bismuth  Ochre. 

§  126.  BiO3,  containing  minute  quantities  of  Fe203,  CuO,  and 
AsO5.  G=4.36.  Occurs  usually  pulverulent  or  earthy. 

Before  the  Blp  it  behaves  like  pure  oxide  of  bismuth.  Soluble  in 
nitric  acid. 

ORES  OP  CHROMIUM. 
Chromic  Iron. 

§  127.  (FeO,  CrO,  MgO)+(Cr203,  APO3).  H=5.5.  G=4.3— 46. 
Occurs  usually  massive ;  of  iron-black  or  brownish-black  color,  with 
a  shining  and  somewhat  metallic  lustre.  Some  varieties  are 
magnetic. 

Heated  in  a  matrass,  remains  unchanged.  Infusible  in  the  for 
ceps.  After  having  been  exposed  to  the  R  Fl  it  follows  the  magnet. 
In  Bx  and  S  Ph  slowly,  but  completely,  soluble  to  a  transparent 
glass,  which  is  beautiful  green  after  cooling.  Mixed  with  Sd  and 
nitre  and  heated  on  platinum-foil,  the  mass  fuses  and  becomes  yel 
low.  With  Sd  on  Ch  in  R  Fl  it  affords  metallic  iron. 

Concentrated  acids  affect  it  but  little,  even  when  finely  pulverized ; 
they  dissolve  only  a  little  iron.  Fused  with  caustic  potassa,  chro- 
mate  of  potassa  is  formed. 

ORES  OF  COBALT. 

Smaltine. 

§  128.  (Co,  Fe,  Ni)  As.H=3.5— 6.  G=6.4— 7.2.  Of  tin-white  or 
steel-gray  color,  and  metallic  lustre. 

In  a  matrass,  usually  yields,  when  heated  to  redness,  a  sublimate 
of  metallic  arsenic.  In  an  open  glass  tube,  affords  a  copious  subli 
mate  of  crystallized  arsenous  acid,  and  sometimes  emits  sulphurous 
acid.  On  Ch  it  fuses  readily,  with  emission  of  copious  arsenical 
fumes,  to  a  grayish-black  magnetic  globule  which,  with  the  fluxes, 
gives  the  indications  of  iron,  cobalt,  and  nickel. 

With  nitric  acid  it  gives  a  pink  solution,  arsenous  acid  being  de 
posited. 


63  ELDERHORST'S  MANUAL  OP 

Cobaltine. 

§  129.  CoS2+CoAs.  11=5.5.  G=6— 6.3.  Of  silver-white  and 
sometimes  reddish  color,  and  metallic  lustre. 

Unchanged  in  the  matrass.  In  an  open  glass  tube,  yields  a  sub 
limate  of  arsenous  acid  and  vapors  of  sulphurous  acid.  On  Ch, 
emits  copious  arsenical  and  sulphur  fumes  and  fuses  to  a  dull  black 
metallic  globule,  which  is  attracted  by  the  magnet,  and  which,  when 
treated  with  fluxes,  gives  the  indications  of  cobalt  and  iron,  and 
sometimes  also  those  of  nickel. 

Dissolves  in  heated  nitric  acid,  arsenous  acid  being  deposited. 

Cobalt  Pyrites  [Linnseite]. 

§  130.  CoS+Co2S3.  H=5.5.  G=4.8— 5.  Of  a  more  or  less 
bright  steel-gray  color,  arid  metallic  lustre.  Crystallizes  in  the 
regular  octahedron. 

In  an  open  glass  tube,  sulphurous  acid  is  abundantly  evolved  and 
sometimes  a  slight  sublimate  of  arsenous  acid  formed.  On  Ch, 
small  pieces  of  the  mineral  readily  fuse  to  a  globule  which,  when 
cold,  is  covered  with  a  black  rough  crust,  and  which  is  attracted  by 
the  magnet.  The  pulverized  mineral,  after  having  been  well  cal 
cined,  dissolves  in  Bx  in  0  Fl  to  a  blue  transparent  glass.  In  a 
highly  saturated  bead  of  this  kind,  when  treated  on  Ch  with  RF1, 
particles  of  metallic  nickel  may  be  seen  floating  about. 

Soluble  in  nitric  acid,  excepting  the  sulphur. 

Cobalt  Bloom  [Erythrine]. 

§131.  3CoO.  As05-f  8110.  H  =  L5— 2.5.  G— 2.9.  Usually  of 
crimson  or  peach-red  color;  when  crystallized,  of  pearly  lustre;  fre 
quently  dull  and  earthy,  forming  incrustations. 

Heated  in  a  matrass,  loses  water,  and  the  color  changes  to  blue 
or  green.  A  small  crystal,  exposed  to  the  inner  flame,  fuses  and 
colors  the  outer  flame  pale-blue.  On  Ch  in  RF1,  emits  arsenical 
fumes  and  melts  to  a  dark-gray  globule  of  arsenide  of  cobalt  which, 
with  fluxes,  gives  the  pure  cobalt-reactions. 

Acids  dissolve  it  readily  to  a  rose-colored  liquid;  the  solution  in 
concentrated  hydrochloric  acid  appears  blue,  while  hot.  The  pul 
verized  mineral  is  partly  decomposed  by  caustic  potassa  ;  the  pow 
der  assumes  a  bluish-gray  color  and  the  solution  is  sapphire-blue. 


BLOW-PIPE  ANALYSIS.  69 

Lavendulan. 

§  132.   AsO5,   CoO,   NiO,    CuO,  and   HO.     H=2.5— 3.     G=3. 

Amorphous,  with  a  greasy  lustre  ;  color  lavender-blue. 

Heated  in  a  matrass,  gives  out  water.  In  the  forceps,  fuses  easily 
and  colors  the  outer  flame  pale-blue  ;  the  fused  mass  becomes  crys 
talline  on  cooling.  On  Ch  in  R  Fl  it  fuses  with  emission  of  arsenical 
fumes.  With  fluxes,  gives  the  reactions  of  Co,  Ni,  and  Cu  (see  §  92). 

Earthy  Cobalt. 

§  133.  It  is  a  variety  of  Wad  (see  §  184),  containing  sometimes 
a  considerable  quantity  of  oxide  of  cobalt,  in  combination  with  silicic 
or  arsenic  acid. 

With  Bx  in  0  FJ,  gives  a  dark-violet  glass,  which  in  the  RF1 
becomes  blue.  The  S  Ph  bead  when  treated  on  Ch  with  metallic 
tin  frequently  exhibits  the  copper-reaction.  With  Sd  on  platinum- 
foil  it  shows  the  presence  of  manganese. 

Soluble  in  hydrochloric  acid  with  evolution  of  chlorine ;  the  solu 
tion  is  usually  blue,  and  on  addition  of  water  becomes  red. 

ORES  OF  COPPER. 

Native  Copper. 

§  134.  Pure  Copper.  H=2.5— 3.  G=8.9.  Of  metallic  lustre, 
and  copper-red  color.  Occurs  usually  massive  or  arborescent. 

It  fuses  on  Ch  to  a  globule  which,  if  the  heat  is  sufficiently  high, 
assumes  a  bright  bluish-green  surface ;  on  cooling  it  becomes  covered 
with  a  crust  of  black  oxide.  With  the  fluxes  it  gives  the  usual  indi 
cations  of  copper. 

It  dissolves  readily  in  nitric  acid. 

Copper  Pyrites  [Chalcopyrite] . 

§  135.  Cu2S-fFe2S3.  H=3.5— 4.  G  =  4.1— 4.3.  Of  a  brass-yel 
low  color  and  metallic  lustre ;  on  exposure  to  moist  air  it  becomes 
iridescent  on  its  surface.  It  occurs  crystallized,  but  usually  mas 
sive.  It  is  easily  scratched  with  a  knife,  giving  a  greenish-black 
powder. 

Heated  in  a  matrass,  decrepitates  and  yields  sometimes  a  faint 
sublimate  of  sulphur,  assuming  at  the  same  time  a  darker  color  or 
becoming  iridescent.  Heated  in  an  open  glass  tube,  sulphurous 
acid  is  given  out  abundantly.  On  Ch,  when  heated,  it  blackens, 


70  ELDERHORST'S  MANUAL  OF 

but  becomes  red  on  cooling;  with  continued  heat  it  fuses  to  a  black 
globule,  which  is  attracted  by  the  magnet ;  this  globule  is  brittle 
and  reddish-gray  in  the  fracture.  The  pulverized  mineral,  after 
roasting,  gives  with  fluxes  the  indications  of  iron  and  copper. 
With  Sd  on  Ch  it  is  reduced;  the  metals  are  obtained  in  separate 
masses.  Moistened  with  hydrochloric  acid  it  colors  the  flame  blue, 
even  previous  to  fusion. 

It  dissolves  in  nitric  acid  and,  more  readily,  in  aqua  regia,  leaving 
a  residue  of  sulphur. 

Purple  Copper  [Erubescite]. 

§  136.  3  Cu>2S-f  Fe2S3.  H=3.  G=4.4— 5.  When  crystalline,  it 
usually  affects  the  cubical  form,  and  is  of  a  pale  yellowish  color; 
when  massive,  its  color  is  copper-red  to  reddish-brown ;  it  speedily 
tarnishes,  assuming  various  hues,  mostly  purple,  blue,  and  reddish. 
When  scratched  with  a  knife  it  gives  a  grayish  powder. 

Before  the  Blp  it  shows  pretty  much  the  same  behavior  as  copper 
pyrites. 

Concentrated  hydrochloric  acid  dissolves  it,  leaving  the  greater 
part  of  the  sulphur  behind. 

Copper  Glance. 

§  137.  Cu2S.  H=2.5— 3.  G=  5.5— 5.8.  Of  a  blackish  lead-gray 
color,  often  with  a  bluish  or  greenish  tint  on  its  surface.  Occurs 
usually  in  compact  masses,  very  often  shining. 

Heated  in  a  matrass,  nothing  volatile  is  given  out.  In  an  open 
tube,  sulphurous  acid  is  evolved.  On  Ch,  readily  fuses  to  a  globule, 
which  boils,  and  emits  glowing  drops,  sulphurous  acid  escaping 
abundantly;  the  outer  flame  is  at  the  same  time  colored  blue. 
With  Sd  on  Ch  it  yields  a  globule  of  metallic  copper. 

In  heated  nitric  acid  it  dissolves,  leaving  a  residue  of  sulphur. 

Gray  Copper  [Tetrahedrite] . 

§  138.  4  (Cu'2S.  FeS.  ZnS)  (SbS3.  AsS3)  frequently  containing 
silver  and  mercury.  H=3 — 4.5.  G=4.5 — 5.  Color  between  steel- 
gray  and  iron-black. 

Heated  in  a  matrass,  fuses  and  finally  yields  a  dark-red  sublimate 
of  tersulphide  of  antimony  with  antimonious  acid.  In  an  open  glass 
tube,  fuses  and  gives  thick  fumes  of  antimony  (and  arsenous  acid), 


BLOW-PIPE    ANALYSIS.  71 

and  sulphurous  acid ;  mercury,  when  present,  condenses  in  the  upper 
part  of  the  tube,  forming  a  metallic  mirror.  On  Ch  it  fuses  readily 
to  a  globule,  emitting  thick  white  fumes  and  sulphur  vapor;  coatings 
of  antimonious  acid  and  of  oxide  of  zinc  are  deposited ;  the  latter  is 
nearer  to  the  assay-piece  and  may  be  tested  with  SoCo  [v.  §  45]. 
To  detect  arsenic,  v.  §  56.  To  detect  mercury,  add  to  the  finely 
pulverized  assay  three  times  its  weight  of  dry  Sd  and  treat  the 
mixture  as  directed  §  91.  The  pulverized  mineral,  after  having 
been  well  roasted,  gives  with  the  fluxes  the  indications  of  iron  and 
copper;  with  Sd,  affords  metallic  copper  and  a  little  iron.  To 
detect  silver,  treat  the  mineral  with  pure  lead  and  Bx  as  directed 
§105. 

When  pulverized  it  is  decomposed  by  nitric  acid,  the  solution 
has  a  brownish-green  color;  antimonious  acid  (and  arsenous  acid) 
and  sulphur  remain  undissolved.  Caustic  potassa  effects  partial 
decomposition  ;  the  sulphide  of  antimony  (and  arsenic)  enters  into 
solution,  and  is,  on  addition  of  an  acid,  re-precipitated. 

Tennantite. 

§  139.  4(Cu2S,  FeS),  AsS3.  H=3.5— 4.  G=4.37— 4.5.  Always 
crystallized  ;  metallic  lustre  ;  color  blackish  lead-gray  to  iron-black. 

In  a  matrass,  gives  a  sublimate  of  tersulphide  of  arsenic.  In  an 
open  tube,  sulphurous  acid  and  a  sublimate  of  arsenous  acid.  On 
Ch,  fuses  easily  with  emission  of  sulphur  and  arsenic  vapors  to  a 
dark-gray  globule,  which  is  attracted  by  the  magnet.  The  pul 
verized  mineral  gives,  after  calcination,  with  fluxes,  the  reaction  of 
iron  and  copper. 

Arsenical  Copper  [Domeykite], 

§  140.  Cu6As.  H=3 — 3.5.  Reniform,  massive,  or  disseminated  ; 
lustre  metallic  ;  color  tin-white  ;  black  and  soft  when  impure. 

Heated  in  a  matrass,  yields  a  little  water  and  a  sublimate  of 
arsenous  acid;  the  assay-piece  assumes  a  silver-white  color.  In 
an  open  tube,  affords  a  "crystalline  sublimate  of  arsenous  acid.  On 
Ch,  fuses  easily  with  emission  of  a  strong  alliaceous  odor  to  a 
yellowish  metallic  mass,  which  gives  the  copper  reactions. 

Readily  soluble  in  nitric  acid  ;  decomposed  by  hydrochloric  acid, 
metallic  arsenic  remaining  undissolved. 


72  ELDERHORST'S  MANUAL  OF 

Atacamite. 

§  141.  CuCl+3CuO-f  3HO.  H=3— 3.5.  G  =  4— 4.3.  Occurs 
crystalline,  or  massive  lamellar ;  color  various  shades  of  bright 
green,  sometimes  blackish-green. 

Heated  in  a  matrass,  gives  out  water  and  a  gray  sublimate, 
which,  on  cooling,  becomes  grayish-white ;  the  water  shows  acid 
reaction.  On  Ch,  fuses  readily,  colors  the  outer  flame  azure-blue, 
and  is  finally  reduced  to  a  globule  of  metallic  copper ;  two  coatings 
are  deposited  on  the  Ch,  the  one  grayish-white,  and  the  other 
brownish,  which,  on  being  played  upon  with  the  II  Fl,  change  their 
place  with  an  azure-blue  tinge. 

Easily  soluble  in  acids. 

Red  Copper. 

§142.  Cu2O.  H=3.5— 4.  G=5.8— 6.  Usually  of  a  very  intense, 
deep  red  color,  occasionally  crimson-red ;  exceedingly  friable. 

Heated  in  the  pincers,  fuses  and  colors  the  outer  flame  emerald- 
green  ;  moistened  with  hydrochloric  acid  and  treated  in  the  same 
manner,  the  color  is  azure-blue.  On  Ch  it  blackens,  then  fuses 
quietly,  and  finally  yields  a  globule  of  metallic  copper  which,  on 
cooling,  becomes  covered  with  a  coating  of  black  oxide. 

Dissolves  readily  in  nitric  acid.  With  hydrochloric  acid  it  gives 
a  brownish  solution,  which  on  addition  of  water  is  decomposed,  a 
white  precipitate  of  subchloride  of  copper  being  formed.  It  is  also 
soluble  in  ammonia :  the  solution  is  colorless  when  the  access  of 
air  is  prevented ;  on  exposure  to  air  it  turns  blue. 

Malachite. 

§143.  2CuO.C02-j-HO.  11=3.5—5.  G=3.7— 4.  Occurs  usually 
in  the  shape  of  mammillated  concretions ;  the  interior  is  very  com 
pact,  and  lustre  shining,  in  the  fracture  sometimes  earthy,  some 
times  silky;  of  a  bright  green  color. 

Heated  in  a  matrass,  gives  out  water  and  turns  black.  On  Ch 
fuses  to  a  globule,  and  affords  metallic  copper  when  the  heat  is  suf- 
!  ciently  high ;  heated  in  the  forceps,  the  outer  flame  is  colored 
green.  With  fluxes  and  Sd  it  behaves  like  oxide  of  copper  (v. 
Table  II,  8). 

It  dissolves  in  acids  with  effervescence  ;  also  soluble  in  ammonia. 


BLOW-PIPE    ANALYSIS.  73 

Azurite  [Blue  Malachite]. 

§144.  2(CuO.C02)  +  CuO.HO.  H=3.5— 4.  G=3.5— 3.8.  Occurs 
usually  crystallized,  or  in  globular  masses  of  columnar  structure. 
It  is  easily  distinguished  by  its  fine  blue  color ;  either  earthy  or 
vitreous  in  lustre. 

Before  the  Blp,  and  to  solvents,  it  behaves  like  malachite.        •  * 

Copper  Vitriol  [Cyanosite]. 

§  145.  CuOS03+5HO.  H=2.5.  G  =  2.21.  Lustre  vitreous ; 
color  various  shades  of  blue ;  taste  metallic  and  nauseous. 

Heated  in  a  matrass,  swells  up.  gives  out  water,  and  becomes 
white.  On  Ch,  colors  the  outer  flame  green,  fuses,  and  affords  a 
button  of  metallic  copper,  crusted  with  a  coat  of  sulphide.  After 
calcination,  gives  with  fluxes  the  reactions  of  copper,  sometimes 
also  those  of  iron. 

Soluble  in  wratcr ;  a  polished  plate  of  iron  introduced  into  the 
solution  becomes  coated  with  copper. 

PJiosplioclialcite. 

§  146.  3CuO.P05-f  3(CuO.HO),  sometimes  2(3CuO.P05)-f  HO 
-H(CuO.HO).  H=4.5— 5.  G=4— 4.4.  Occurs  both  crystallized 
and  massive.  Of  adamantine  lustre,  and  dark  emerald-green  or 
blackish-green  color. 

In  a  matrass,  gives  out  water  and  blackens.  A  piece,  previously 
heated  in  a  matrass,  fuses  in  the  forceps  to  a  black  globule,  which 
becomes  crystalline  on  cooling.  With  Bx  and  S  Ph,  behaves  like 
oxide  of  copper.  Strongly  heated  on  Ch  with  a  sufficient  quantity 
of  Sd,  nearly  all  the  copper  is  obtained  as  a  metallic  globule. 
Mixed  with  an  equal  volume  of  metallic  lead  and  fused  on  Ch,  a 
globule  of  metallic  copper  is  obtained,  surrounded  by  a  fused  mass 
of  phosphate  of  lead,  which  on  cooling  crystallizes. 

Soluble  in  nitric  acid,  and  in  caustic  ammonia. 

Olivenite. 

§  147.  3CuO.  (As05.P05)  +  CuO.HO.  H=3.  G=4.1— 4.4. 
Crystallized,  or  in  globular  and  reniform  masses,  of  indistinctly 
fibrous  structure.  Color  usually  olive-green. 

In  a  matrass,  yields  a  little  water.  In  the  forceps,  fuses  to  a 
globule  and  colors  the  outer  flame  bluish-green ;  the  fused  mass 
7 


74  ELDERHORST'S  MANUAL  OP 

crystallizes  on  cooling.  On  Ch,  fuses  with  detonation  and  emission 
of  arsenical  vapors  to  a  metallic  globule ;  the  globule  is  white  and 
somewhat  brittle,  and  covered  with  a  brown  scoria.  Fused  with 
metallic  lead,  it  is  decomposed  in  the  same  manner  as  the  pre 
ceding  ore. 

Dissolves  in  nitric  acid,  also  in  ammonia. 

Tyrolite. 

§148.  [(3CuO.As05+SHO)  +  2(CuO.HO)]  +  CaO.C02.  H=l- 
2.  G=3.  Usually  reniform,  massive;  structure  radiate  foliaceous. 
Color  pale-green.  Very  sectile. 

Heated  in  a  matrass,  decrepitates,  yields  much  water,  and  black 
ens.  On  Ch,  fuses  with  emission  of  arsenical  vapors  to  a  gray 
scoriaceous  mass,  in  which  minute  globules  of  metallic  copper 
occasionally  appear.  When  the  mineral  is  fused  on  Ch,  with 
addition  of  Sd  and  Bx,  until  the  oxide  of  copper  is  completely 
reduced  and  the  slag  dissolved  in  hydrochloric  acid,  a  solution 
is  obtained  in  which  the  presence  of  lime  may  be  shown  by  the 
proper  reagents. 

Dissolves  in  nitric  acid  with  effervescence,  also  in  ammonia. 
ChrysocoUa. 

§  149.  3CuO.  2Si03-f  6HO.  11=2—3.  G=2.  Occurs  usually 
as  an  incrustation.  It  very  much  resembles  malachite  ;  its  color  is 
bluish-green,  and  it  is  remarkable  for  its  great  compactness ;  its 
surface  is  very  smooth,  giving  it  the  appearance  of  an  enamel  or  a 
well-fused  slag. 

In  a  matrass,  yields  water  and  blackens.  In  the  forceps  infusible, 
coloring  the  outer  flame  intensely  green.  On  Ch  in  0  Fl  blackens, 
in  R  Fl  turns  red.  S  Ph  and  Bx  dissolve  it  with  the  usual  indica 
tions  of  copper ;  the  S  Ph  bead  shows  a  cloud  of  undissolved  silica. 
With  Sd  on  Ch,  affords  globules  of  metallic  copper. 

It  is  decomposed  by  acids,  silica  remaining  undissolved. 

ORES  OF  GOLD,  PLATINUM,  AND  IRIDIUM. 

Native  Gold. 

§  150.  Combination  of  Au  and  Ag  in  variable  proportions,  some 
times  with  traces  of  Fe  and  Cu.  H=2.5— 3.  G=  15.6— 19.5. 


BLOW-PIPE    ANALYSIS.  75 

Easily  distinguished  by  its  malleability,  its  cutting  like  lead,  its 
high  specific  gravity,  and  its  resistance  to  acids.  Color  and  streak 
various  shades  of  gold-yellow.  It  usually  occurs  in  variously  con 
torted  and  branched  filaments,  in  scales,  in  plates,  or  in  small 
irregular  masses. 

On  Ch,  fuses  to  a  globule  which,  after  cooling,  has  a  bright 
metallic  surface.  With  SPh  in  OF1,  a  bead  is  formed  which 
opalizes  on  cooling,  or  becomes  opaque  and  yellow,  according  to 
the  amount  of  silver  which  it  contains. 

Resists  the  action  of  heated  concentrated  nitric  acid ;  soluble 
only  in  aqua  regia. 

Graphic  Tellurium  [Sylvanite]. 

§  151.  AgTe+2AuTe3.  H=1.5— 2.  G  =  5.f.  Of  metallic  lustre 
and  steel-gray  color.  Very  sextile. 

In  an  open  glass  tube,  yields  a  white  sublimate  which,  when 
played  upon  with  the  flame,  fuses  to  transparent  drops.  On  Ch, 
fuses  to  a  dark-gray  globule,  depositing  at  the  same  time  a  white 
Ct  which,  when  touched  with  the  RF1,  disappears,  tinging  the  flame 
bluish-green  (see  §§  29,  35).  It  finally  affords  a  light-yellow  malle 
able  globule  of  metallic  lustre. 

Soluble  in  aqua  regia,  leaving  a  residue  of  chloride  of  silver.  The 
solution  gives  a  white  precipitate  with  water. 

Native  Platinum. 

§  152.  Pt,  usually  combined  with  a  little  Fe,  Ir,  Os,  Pd,  Rh,  and 
sometimes  Cu  and  Pb. 

H=4 — 4.5.  G=16 — 19.  Usually  occurs  in  grains  of  silver- 
whitish  or  gray  color,  malleable  and  ductile. 

Infusible  before  the  Blp  and  not  acted  upon  by  fluxes.  Soluble 
only  in  heated  aqua  regia.  The  solution  gives  a  yellow  granular 
precipitate  with  chloride  of  potassium. 

Osm ium-Iridium  [Iridosmine] . 

§  153.  The  light  variety  IrOs3  and  IrOs4.  11=6— f.  G=19.3— 
21.1.  Occurs  usually  in  irregular  flattened  grains,  of  metallic  lustre 
and  tin-white  color  ;  but  little  malleable. 

Infusible  before  the  Blp  ;  when  fused  with  nitre  in  a  matrass,  the 
characteristic  osmium  odor  is  produced.  The  fused  mass  is  soluble 


76  ELDERHORST'S  MANUAL  OF 

in  water ;  the  solution  gives,  on  addition  of  nitric  acid,  a  green  pre 
cipitate.     The  dark  varieties  lose  before  the  Blp  the  metallic  lustre, 
and,  when  held  in  the  alcohol  flame,  impart  to  it  a  yellowish-red 
color  and  great  luminating  power. 
Not  visibly  affected  by  any  acid. 

ORES  OF  IRON. 

Meteoric  Iron. 

§  154.  Fe  with  variable  quantities  of  Ni  (from  1  to  20  per  cent.) 
and  traces  of  Co,  Mg,  Mn,  Sn,  Cu,  Cr,  Si,  C,  Cl,  S,  and  P.H=4.5. 
G=7.3 — 7.8,  rarely  as  low  as  6.  Lustre  metallic  ;  color  iron-gray  ; 
ductile  ;  strongly  attracted  by  the  magnet. 

Infusible.  On  Ch  with  Bx  or  S  Ph  gives  only  the  reactions  of 
iron.  To  detect  the  presence  of  the  other  heavy  metals,  the  assay- 
piece  must  be  dissolved  in  aquaregia,  the  liquid  mixed  with  ammonia 
in  excess,  filtered,  and  the  ammoniacal  filtrates  precipitated  with 
sulphydrate  of  ammonia.  The  precipitate  consists  of  the  sulphides 
of  nickel,  cobalt,  manganese,  and  copper,  which  may  be  collected  on 
a  filter  and  treated  with  Bx  on  Ch  as  described  §  70. 

Brown  Hematite  [Liinonite]. 

§  155.  2  Fe203.  3110.  11=5—5.5.  G=3.6— 4.  Of  a  dull 
brownish-yellow  color,  earthy  or  semi-metallic  in  appearance,  and 
often  in  mammillary  or  stalactitic  forms. 

In  a  matrass,  yields  water,  and  red  sesquioxide  remains  ;  in  pla 
tinum  forceps,  fusible  on  the  edges  ;  gives  with  Bx  and  S  Ph  an 
iron  reaction ;  the  clayey  varieties  treated  with  S  Ph  give  a  cloud 
of  undissolved  silica ;  treated  with  Sd  and  nitre  on  platinum-foil, 
the  manganese  reaction  is  almost  always  obtained. 

Specular  Iron  [Hematite]. 

§156.  Fe203.  11=5.5—6.5.  G=4.5— 5.3.  Of  a  dark  steel-gray 
or  iron-black  color,  and  usually  of  metallic  lustre  ;  its  powder  is  red. 

Infusible  alone  ;  becomes  magnetic  after  roasting,  and  gives  the 
usual  indications  of  iron  with  the  fluxes ;  its  powder  dissolves  read 
ily  in  heated  hydrochloric  acid.  Contains  sometimes  chromium  and 
titanium,  which  may  be  detected  by  the  processes  given  in  §§  68 
and  111. 


BLOW-PIPE    ANALYSIS.  77 

Magnetic  Iron  Ore  [Magnetite]. 

§  157.  FeO.  Fe203.  11=5.5—6.5.  G=4.9— 5.2.  Its  color  is  iron- 
black,  with  a  shining  metallic  or  glimmering  lustre  ;  its  powder  is 
black ;  it  is  strongly  attracted  by  the  magnet. 

It  fuses  with  difficulty,  and  gives  the  usual  reactions  of  iron  with 
the  fluxes ;  the  pulverized  mineral  dissolves  completely  in  hydro 
chloric  acid. 

Iron  Pyrites. 

§158.  FeS2.  H=6 — 6.5.  G=4.8— 5.  Occurs  commonly  in  cubes. 
Usually  of  a  brass-yellow  color  and  metallic  lustre.  By  its  supe 
rior  hardness,  not  yielding  to  the  knife,  and  emitting  sparks  when 
struck  with  steel,  it  may  be  distinguished  from  copper  pyrites. 

Heated  in  a  glass  tube  closed  at  one  end,  usually  emits  some 
sulphuretted  hydrogen,  and  yields  a  sublimate  of  sulphur;  the 
residue  is  attracted  by  the  magnet.  Heated  on  Ch  with  the  O  Fl, 
the  sulphur  burns  off  with  a  blue  flame,  and  leaves  red  oxide  be 
hind,  which,  when  treated  with  the  fluxes,  gives  pure  iron  reactions. 
But  slightly  affected  by  hydrochloric  acid ;  nitric  acid  dissolves  it, 
leaving  a  residue  of  sulphur. 

White  Iron  Pyrites  [Marcasite]. 

§  159.  FeS-.  H=6— 6.5.  G= 4.6— 4.8.  Crystals  are  prismatic. 
Color  usually  light  bronze-yellow,  sometimes  inclined  to  green  or 
gray  ;  occurs  frequently  in  radiated  masses  or  crest-like  aggrega 
tions.  Yery  liable  to  decomposition. 

Before  the  Blp  it  behaves  like  the  preceding. 

Magnetic  Pyrites  [Pyrrhotine]. 

§  160.  5FeS-f  Fe'S3.  H=3.5— 4.5.  0=4.4—4.7.  Very  much 
resembles  common  iron  pyrites,  from  which  it  is  distinguished  by 
its  inferior  hardness,  and  by  being  slightly  attracted  by  the  magnet. 

Heated  in  a  matrass,  remains  unchanged ;  in  the  open  glass  tube, 
emits  sulphurous  acid  but  yields  no  sublimate.  On  Ch  in  RF1, 
fuses  to  a  globule,  which  is  covered  with  an  uneven  black  coating, 
which  follows  the  magnet,  and  which,  on  a  surface  of  fracture,  ex 
hibits  a  yellowish  crystalline  structure  and  metallic  lustre.  In 
OF1  it  is  converted  into  red  oxide. 
7* 


78  ELDERHORST  S    MANUAL    OF 

Soluble  in  hydrochloric  acid,  excepting  the  sulphur,  with  evolu 
tion  of  sulphuretted  hydrogen. 

Arsenical  Pyrites  [Mispickel]. 

§  161.  FeS2+FeAs.  11=5.5—6.  G=5— 6.4.  Of  metallic  lustre 
and  a  silver-white  color.  Streak  dark  grayish-black.  Brittle. 

Heated  in  a  matrass,  yields  first  a  red  sublimate  of  sulphide  of 
arsenic,  and  afterwards  a  black  crystalline  one  of  metallic  arsenic  j 
in  an  open  glass  tube,  yields  arsenous  acid  and  sulphurous  acid. 
On  Ch,  emits  copious  arsenical  fumes,  and  a  Ct  of  arsenous  acid  is 
deposited ;  then  fuses  to  a  globule  which  shows  the  properties  of 
fused  magnetic  pyrites.  Frequently  contains  cobalt,  the  presence 
of  which  may  be  detected  by  the  method  described  in  §  69. 

Soluble  in  nitric  acid  and  aqua  regia,  leaving  a  residue  of  sulphur 
and  arsenous  acid ;  the  latter  dissolves  with  continued  digestion. 

TUaniferous  Iron  [Ilmenite]. 

§162.  Ti2O3  and  Fe203  in  various  proportions.  11  =  5—6. 
G=5.5 — 5.  Of  iron-black  color,  usually  in  tabular  crystals,  bears 
a  great  resemblance  to  specular  iron,  but  gives  no  red  powder. 

Alone  in  the  OF1  infusible ;  in  RF1  it  may  be  rounded  at  the 
edges.  With  Bx  and  SPh  in  OF1,  gives  the  reactions  of  pure  oxide 
of  iron  ;  but  the  SPh  bead  when  treated  with  the  RFl  assumes  a 
brownish-red  color,  the  intensity  of  which  depends  upon  the  amount 
of  titanic  acid  present ;  this  glass,  when  treated  with  tin  on  Ch, 
turns  violet  (v.  Table  II,  23).  To  show  conclusively  the  presence 
of  Ti,  follow  the  method  given  in  §  111. 

Dissolved  by  hydrochloric  acid  and  aqua  rcgia  with  separation 
of  titanic  acid ;  some  varieties  dissolve  with  great  difficulty,  even 
when  reduced  to  a  very  fine  powder. 

Spathic  Iron  [Clialybite]. 

§  163.  FeO.CO2.  11=3.5—4.5.  G=3.7— 3.9.  Color  from  grayish- 
yellow  to  reddish-brown ;  crystallizes  in  rhombohedrons,  which  are 
often  curved,  and  are  very  distinctly  cleavable  ;  often  massive. 

Heated  in  a  matrass,  frequently  decrepitates,  carbonic  acid  and 
carbonic  oxide  are  given  out,  and  a  black  oxide  of  iron  remains, 
which  is  attracted  by  the  magnet.  Alone,  infusible.  With  Bx  and 
SPh  it  gives  the  pure  iron  reactions,  and  with  Sd  sometimes  those 


BLOW-PIPE    ANALYSIS.  79 

of  manganese.     It  dissolves  in  strong  acids  with  effervescence,  but 
with  difficulty,  and  only  when  pulverized. 
Green  Vitriol  [Copperas]. 

§  164.  FeO.  So3+7HO.  H=2.  G=1.83.  Occurs  usually  massive 
and  pulverulent,  of  various  shades  of  green,  becoming  yellowish  on 
exposure  to  air ;  taste  astringent  and  metallic. 

In  a  matrass,  gives  out  sulphurous  acid  and  water,  which  shows 
acid  reaction.  Strongly  heated,  only  sesquioxide  of  iron  remains. 

Soluble  in  water. 
Vivianite. 

§  165.  6(3FeO,Po5-f  8HO)-f  (3Fe203,2P05+ SHO).  H=1.5— 2. 
G=2.66.  Occurs  crystallized,  or  in  reniform  and  globular  masses, 
sometimes  as  incrustation.  Color  blue  to  green,  usually  dirty  blue. 

In  a  matrass,  swells  and  gives  pure  water.  In  the  forceps,  fuses 
to  a  steel-gray  metallic  globule,  coloring  the  outer  flame  bluish- 
green.  With  fluxes  gives  the  reactions  of  iron. 

Easily  soluble  in  hydrochloric  acid  and  nitric  acid.  With  a  solu 
tion  of  caustic  potassa,  it  blackens. 

jScorodite. 

§  166.  Fe203,As05-f  4HO.  H=3.5— 4.  G=3.1— 3.3.  Crystal 
lized.  Color  pale  leek-green  or  liver-brown. 

In  a  matrass,  yields  pure  water.  In  the  forceps,  fuses  to  a  gray 
scoriaceous  slag  of  metallic  lustre,  coloring  the  outer  flame  pale-blue. 
On  Ch,  emits  arsenical  vapors  and  fuses  to  a  gray  magnetic  slag, 
of  metallic  lustre,  which  gives  with  fluxes  the  reactions  of  iron. 

Not  affected  by  nitric  acid ;  forms  a  brown  solution  with  hydro 
chloric  acid;  partially  dissolved  by  ammonia,  leaving  a  brown 
residue. 

ORES  OF  LEAD. 

Plumbic  Ochre. 

§  167.  PbO,  containing  frequently  PbO.CO2,  CaO,  Fe203,  and 
SiO3.  G=8.  Massive.  Lustre  dull;  color  between  sulphur  and 
orpiment-yellow. 

Before  the  Blp,  behaves  like  oxide  of  lead. 

Minium. 

§168.  PbO,Pb203.  G=4.6.  Pulverulent.  Color  vivid  red,  mixed 
with  yellow. 


80  ELDERIIORST'S  MANUAL  OP 

Before  the  Blp,  behaves  like  oxide  of  lead. 

With  hydrochloric  acid,  evolves  chlorine  and  is  converted  into 
chloride  of  lead.  With  nitric  acid,  becomes  brown. 

Galena. 

§  169.  PbS.  11=2.5—2.75.  G  =  7.25— 7.7.  Color,  lead-gray;  of 
metallic  lustre.  Crystals  usually  affect  the  cubical  form,  and  pos 
sess  very  perfect  cubic  cleavage. 

Heated  in  a  matrass,  sometimes  decrepitates  and  frequently 
yields  a  slight  white  sublimate.  Heated  in  an  open  glass  tube, 
emits  sulphurous  acid,  and,  on  the  heat  being  raised,  gives  a 
white  sublimate  of  sulphate  of  lead.  Heated  on  Ch,  affords  a  glo 
bule  of  pure  lead,  the  Ch  becoming  at  the  same  time  covered  with 
sulphate  of  lead  and  oxide  of  lead.  The  globule  of  metallic  lead 
yields  generally  a  little  silver  on  cupellation.  The  presence  of 
antimony  is  ascertained  as  shown  §  49.  Zinc,  §  113.  Iron,  §  83. 

It  dissolves  with  some  difficulty  in  boiling  hydrochloric  acid, 
with  evolution  of  sulphuretted  hydrogen.  Very  dilute  nitric  acid 
has  no  effect  on  it,  but  by  a  stronger  acid  it  is  readily  dissolved 
with  evolution  of  nitrous  acid  vapors.  By  fuming  nitric  acid  and 
aqua  regia  it  is  very  violently  acted  upon,  being  converted  into 
sulphate,  or  a  mixture  of  the  sulphate  with  the  chloride. 

Bournonite. 

§  170.  3Cu2S,SbS3+2(3PbS,SbS3).  11^2.5—3.  G=  5.7— 5.9. 
Occurs  crystallized,  and  massive,  granular,  compact;  lustre  metallic; 
color  and  streak  steel-gray. 

In  a  matrass,  decrepitates  and  yields  with  a  strong  heat  a  dark- 
red  sublimate.  In  an  open  tube,  sulphurous  acid  is  evolved  and 
abundant  antimonial  fumes,  which  condense  partly  on  the  upper 
and  partly  on  the  lower  side  of  the  tube;  the  former  consist  of  anti- 
monious  acid,  which  is  volatile;  the  latter  is  not  volatile,  and  con 
sists  of  a  mixture  of  antimonate  of  oxide  of  antimony  with  afitimo- 
nate  of  lead.  On  Ch,  fuses  readily  to  a  black  globule  and  deposits  a 
Ct  of  antimonious  acid ;  with  strong  heat  a  Ct  of  oxide  of  lead  is 
obtained;  the  remaining  globule,  when  treated  with  Bx  in  OF1, 
gives  the  reactions  of  copper,  and  the  globule  assumes  the  appear 
ance  of  metallic  copper. 


BLOW-PIPE   ANALYSIS.  81 

Dissolves  readily  in  nitric  acid  to  a  blue  liquid,  leaving  a  residue 
of  antimonious  acid  and  sulphur.  Aqua  regia  leaves  a  residue  of 
sulphur,  chloride  of  lead,  and  antimonite  of  lead ;  the  solution  gives 
a  precipitate  with  water.  Ammonia  dissolves  a  portion  of  the 
sulphide  of  antimony. 

The  following  ores  behave  before  the  Blp  in  a  very  similar  manner. 

Geocronite.    PbS,  (SbS3,  AsS3)-f  4PbS. 

Dufrenoysite.    PbS,  AsS3+Pbs. 

Boulangerite.    PbS,  SbS3+2PbS. 

Heteromorphite.    PbS,  SbS3-f  PbS. 

Jamesonite.    2(PbS,  SbS3)-f  PbS. 

Plagionite.    3(PbS,  SbS3)+PbS. 

Zinkcnite.    PbS,  SbS3. 

Those  minerals  in  which  a  part  of  the  SbS3  is  substituted  by 
AsS3,  give  on  Ch  arsenical  vapors,  and  in  an  open  tube  a  crystalline 
sublimate. 

Cerazine  [Corneous  Lead]. 

§  171.  PbCl+PbO.CO8.  11  =  2.75—3.  G=6— 6.3.  Forma, 
crystals  of  adamantine  lustre,  of  white,  gray,  or  yellow  color. 

In  a  matrass,  decrepitates  slightly  and  becomes  a  little  darker- 
yellow.     On  Ch,  fuses  readily,  emits  acid  vapors,  becomes  reduced 
to  metallic  lead,  and  gives  a  white  Ct  of  chloride  of  lead  and  a: 
yellow  Ct  of  oxide. 

Dissolves  in  nitric  acid  with  effervescence. 

White  Lead  Ore  [Cerusite]. 

§  172.  PbO.  CO2.  11=3—3.5.  G=6.4.  Occurs  granularly 
massive,  or  in  prismatic  needles,  or  compressed  plates.  Color 
mostly  white,  yellow,  or  gray. 

When  heated  in  a  matrass,  decrepitates  and  turns  yellow ;  car 
bonic  acid  is  given  out.  Heated  on  Ch  alone,  is  reduced  to  metallic 
lead.  Treated  with  fluxes,  dissolves  with  effervescence  and  gives 
the  reactions  of  pure  oxide  of  lead  (v.  Table  II,  12) ;  dissolves 
readily  and  with  effervescence  in  dilute  nitric  acid;  with  hydro 
chloric  acid,  leaves  a  residue  of  chloride  of  lead;  dissolves  in  a, 
solution  of  caustic  potassa. 


82  ELDERHORST'S  MANUAL  OF 

LcadJiilUte. 

§  173.  PbO.  S03-f  3(PbO.C02).  H=2.5.  G=G.2— 6.5.  Occurs 
in  transparent  crystals  of  pearly  or  resinous  lustre.  Color  white, 
passing  into  yellow,  green,  or  gray. 

On  Ch,  intumesces  slightly,  becomes  yellow,  but  white  again  on 
cooling ;  with  greater  heat  easily  reduced  to  metallic  lead. 

Dissolves  in  nitric  acid  with  effervescence,  leaving  a  residue  of 
sulphate  of  lead. 

Lead  Vitriol  [Anglesite]. 

§  174.  PbO.  SOI  H=2.75— 3.  G=6.2.  It  often  occurs  in 
small  octahedral  crystals  with  many  facets,  but  more  frequently  in 
laminar  masses  ;  of  high  lustre. 

Heated  in  a  matrass,  decrepitates  and  usually  yields  a  little 
water.  Treated  on  Ch  in  OF1,  fuses  to  a  clear  bead,  wrhich  on 
cooling  turns  milk-white  ;  with  Sd  on  Ch,  affords  a  globule  of 
metallic  lead ;  the  Sd  is  absorbed  by  the  Ch  and  shows,  when  placed 
on  silver-foil,  a  strong  sulphur  reaction.  With  the  fluxes,  gives  the 
reactions  of  oxide  of  lead.  Traces  of  iron  or  manganese  may  be 
detected  by  Bx  or  Sd  as  shown  §§  83  and  90. 

It  dissolves  in  acids  only  with  great  difficulty ;  by  hydrochloric 
acid  it  is  partly  decomposed ;  the  pulverized  mineral  is  soluble  in  a 
solution  of  caustic  potassa. 

Phosphate  of  Lead  [Pyromorphite]. 

§175.  Essentially  PbCl+3(3PbO.[P05.As05]).  11=3.5— 4.  G  = 
6.5 — 7.  It  occurs  often  in  globular  masses  with  a  columnar  struc 
ture,  also  fibrous  and  granular.  Color  green,  yellow,  and  brown. 

Heated  in  a  matrass,  sometimes  decrepitates  and  yields,  with 
continued  heat,  a  faint  white  and  volatile  sublimate  of  chloride  of 
lead.  Heated  in  the  platinum-pointed  pincers,  fuses  readily  and 
colors  the  outer  flame  blue;  if  the  amount  of  phosphoric  acid  is« 
not  too  small,  the  edges  of  the  flame  will  appear  green.  With  SPh 
and  oxide  of  copper,  gives  the  reaction  for  chlorine,  §  C5.  On  Ch 
in  the  0  Fl,  fuses  to  a  globule,  which  on  cooling  assumes  a  poly 
hedral  form  and  a  dark  color ;  in  the  R  Fl,  yields  a  Ct  of  oxide  of 
lead,  and  the  globule,  on  cooling,  assumes  dodecahedral  facets  of 
pearly  lustre.  With  boracic  acid  and  iron  wire,  gives  the  reaction 
for  phosphoric  acid  (§  95).  With  Sd  on  Ch,  affords  metallic  lead. 


BLOW-PIPE  ANALYSIS.  83 

Some  varieties  contain  arsenic  acid,  which  is  readily  detected  by 
the  odor  when  treated  with  Sd  on  Ch  (§  54). 

Soluble  in  nitric  acid,  and  solution  of  caustic  potassa. 

Plum  bo-Resinite. 

§  176.  3PbO.  P05-f  6(A1203,3HO).  H=4— 4.5.  G=6.3— 6.4. 
In  reniform  or  globular  masses,  with  a  columnar  structure;  also 
compact  massive.  Of  resinous  lustre ;  color  usually  yellowish-brown ; 
resembling  gum-arabic  in  appearance. 

In  a  matrass,  decrepitates  and  gives  out  water.  In  the  forceps, 
intumesces  and  colors  the  outer  flame  azure-blue.  On  Ch,  intu- 
mesces,  becomes  white  and  opaque,  and  fuses  but  imperfectly,  de 
positing  a  faint  white  Ct  of  chloride  of  lead.  In  small  quantities, 
soluble  in  Bx  and  SPh  to  clear  beads.  With  Sd  on  Ch,  minute 
globules  of  metallic  lead  are  obtained.  Treated  with  SoCo,  assumes 
a  fine  blue  color. 

Soluble  in  nitric  acid. 

Red  Lead  Ore  [Crocoisite] . 

§  177.  PbO.  CrO3.  H=2.5— 3.  G=5.9— 6.1.  Occurs  usually  in 
bright  hyacinth-red  crystals  of  adamantine  lustre. 

In  a  matrass,  decrepitates;  the  crystals  are  broken  up  into  minute 
pieces  and  assume  a  darker  color.  On  Ch,  fuses  and  becomes  re-> 
duced  with  detonation ;  a  Ct  of  oxide  of  lead  is  formed,  and  grayish- 
green  sesquioxide  of  chromium  remains  with  the  metallic  globule. 
With  Sd  on  Ch,  affords  a  globule  of  metallic  lead.  With  Sd  on 
platinum  foil,  fuses  to  a  dark-yellow  mass,  which  becomes  green  in 
RF1.  With  Bx  or  SPh  in  OF1,  dissolved;  the  bead  appears 
yellow  wrhile  hot,  but  becomes  green  on  cooling.  Fused  in  a 
platinum  spoon  with  from  3  to  4  parts  of  bisulphate  of  potassa, 
gives  a  dark-violet  mass,  which  is  greenish-white  when  cold. 

Dissolves  in  heated  hydrochloric  acid  to  a  green  liquid,  leaving 
a  residue  of  chloride  of  lead.     Dissolves  with  difficulty  in  nitric 
acid  to  a  yellowish-red  liquid.     A  solution  of  caustic  potassa  colors 
it  brown,  and  finally  dissolves  it  to  a  yellow  liquid. 
VauqueUnite. 

§  178.  3CuO,2Cr03-f  2(3PbO,2Cr03).  H=2.5— 3.  G=5.5— 5.7. 
Occurs  usually  in  minute  crystals,  or  in  reniform  or  granular  masses. 
Color  dark-green  to  brown,  sometimes  nearlv  black. 


84  ELDERIIORST'S  MANUAL  OP 

On  Ch,  fuses  with  effervescence  to  a  gray  submetallic  globule; 
where  the  mass  is  in  contact  with  the  coal,  small  globules  of  lead 
make  their  appearance;  in  RF1  a  Ct  of  oxide  of  lead  is  formed. 
With  Bx  or  SPh  in  0  Fl,  clear  green  beads  are  obtained,  which 
remain  green  on  cooling,  but  which  on  application  of  the  RF1  be 
come  red  and  opaque ;  this  reaction  appears  most  distinctly  on  Ch 
with  Sn.  With  Sd  on  platinum  wire  in  OF1,  dissolves  to  a  trans 
parent  green  bead,  which  on  cooling  becomes  yellow  and  opaque; 
on  treating  the  bead  with  a  few  drops  of  water,  a  yellow  solution 
is  obtained,  in  which  the  presence  of  chromic  acid  may  be  proved 
as  described  §  68.  With  Sd  on  Ch,  is  completely  decomposed;  on 
treating  the  reduced  metals  with  boracic  acid  on  Ch  (v.  §  71)  a 
globule  of  metallic  copper  is  obtained. 

Partly  soluble  in  nitric  acid  to  a  dark  green  liquid;  the  residue 
is  yellow. 

Wulfenite  [Yellow  Lead  Ore]. 

§  179.  PbO,  MoO3,  sometimes  with  a  little  CrO3.  11=2.75—3. 
G=6.3 — 6.9.  Crystallized  or  granularly  massive,  firmly  coherent. 
Color  usually  wax-yellow,  passing  into  orange-yellow. 

In  a  matrass,  decrepitates  and  becomes  darker  while  hot.  On 
Ch,  fuses  and  is  partly  absorbed  by  the  coal,  while  metallic  lead  and 
a  Ct  of  oxide  of  lead  are  deposited.  With  Bx  or  SPh  on  platinum 
wire  gives  the  reactions  of  molybdic  acid  (v.  Table  II,  15).  With 
Sd  on  Ch,  affords  a  globule  of  metallic  lead.  Fused  with  bisulphate 
of  potassa  in  a  platinum  spoon,  a  yellowish  mass  is  obtained,  which 
becomes  white  on  cooling  ;  treated  with  distilled  water  and  a  piece 
of  metallic  zinc  placed  into  the  solution,  the  liquid  assumes  a  blue 
color. 

Dissolves  in  concentrate  hydrochloric  acid  to  a  green  liquid, 
leaving  a  residue  of  chloride  of  lead.  The  pulverized  mineral  is 
decomposed  on  being  digested  with  nitric  acid;  a  yellowish-white 
residue  is  left,  which  becomes  blue  when  exposed  to  air  in  thin 
layers. 

ORES  OF  MANGANESE. 

Pyrolmite  [Gray  Ore  of  Manganese]. 
§  180.  MnOl    11=2—2.5.    G=4.8.     Of  black  or  dark-gray  color 
and  little  lustre ;  powder  black  ;  sometimes  of  columnar  structure. 


BLOW-PIPE    ANALYSIS.  85 

In  a  matrass,  usually  yields  a  little  water ;  when  heated  to  red 
ness,  oxygen  is  evolved.  Alone  infusible,  but  turning  reddish- 
brown  when  the  temperature  is  sufficiently  high.  Soluble  in  Bx 
and  SPh  with  the  usual  manganese-reactions ;  gives  frequently  the 
indications  of  iron. 

Soluble  in  hydrochloric  acid  with  disengagement  of  chlorine. 

ffausmannite  [Black  Manganese]. 

§181.  MnO,Mn203.  H=5— 5.5.  G=4.7.  Crystallized,  or 
granular,  particles  strongly  coherent.  Color  brownish-black  ;  streak 
chestnut-brown. 

Before  the  Blp,  and  to  hydrochloric  acid  behaves  like  the  pre 
ceding  ore. 

Braunite. 

§  182.  Mn203.  H==6— 6.5.  G=4.7— 4.8.  Occurs  crystallized 
or  massive.  Color  and  streak  dark  brownish-black. 

In  a  matrass,  does  not  give  any  water ;  behaves  otherwise  like 
pyrolusite.  Dissolves  in  hydrochloric  acid  with  disengagement  of 
chlorine,  leaving  sometimes  a  residue  of  silica. 

Psilomelane. 

§  183.  Composition  very  various,  essentially  MirO3  with  BaO  or 
KO,  and  HO.  H=5— 6.  G=3.7— 4.3.  Massive.  Color  iron- 
black  ;  streak  brownish-black,  shining. 

Before  the  Blp  and  to  solvents  it  behaves  like  pyrolusite. 
Wad  [Bog  Manganese]. 

§  184.  Essentially  MnO2,  MnO,  and  HO ;  contains  often  Fe2O3, 
APO3,  BaO,  SiO3,  &c.  H=0.5— 6.  G=3— 4.2.  Amorphous, 
earthy  or  compact,  of  a  dull  black  color. 

In  a  matrass,  yields  water  abundantly,  and  otherwise  behaves 
like  pyrolusite.     Some  varieties,  known  under  the  name  of  "  Cu 
preous  Manganese,"  when  treated  with  Sd  and  Bx  on  Ch,  afford  a 
globule  of  metallic  copper. 
Diallogite. 

§  185.  MnO,C02  when  pure,  sometimes  (MnO,  FeO,  CuO,  MgO), 
CO2.  H=3.5 — 4.5.  G=3.4 — 3.6.   Occurs  crystallized,  or  in  globular 
masses  of  columnar  structure  ;  also  massive.     Color  shades  of  rose- 
red,  brownish  ;  streak  white. 
8 


86  ELDERIIORST'S  MANUAL  OF 

In  a  matrass,  some  varieties  give  a  little  water  and  decrepitate 
violently.  Infusible.  Some  varieties,  when  heated  in  R  Fl,  become 
magnetic.  Dissolves  in  fluxes  with  effervescence  and  gives  usually 
the  reaction  of  manganese  and  iron. 

The  pulverized  mineral  is  little  affected  by  hydrochloric  acid  in 
the  cold ;  on  heating  dissolves  with  effervescence. 

Franldinite. 

§180.  ZnO,  Mn'03-M  Fe203.  11=5.5— £.5.  G=5.  Occurs 
crystallized,  and  massive.  Lustre  metallic  ;  color  iron-black ;  streak 
dark  reddish-brown  ;  acts  slightly  on  the  magnet. 

Infusible.  Dissolves  in  Bx  and  S  Ph  with  manganese-reaction  ; 
the  Bx  bead,  when  treated  on  Ch  in  II  Fl,  becomes  bottle-green. 
With  Sd  on  platinum  foil,  gives  manganese-reaction.  With  Sd  on 
Ch,  gives  a  faint  Ct  of  oxide  of  zinc,  which  becomes  more  distinct 
on  addition  of  Bx. 

Dissolves  completely  in  heated  hydrochloric  acid  to  a  greenish- 
yellow  liquid,  chlorine  being  evolved. 

ORES  OF  MERCURY. 

Native  Mercury. 

§  187.  Hg,  sometimes  containing  a  little  Ag.  G  =  13.5  Metallic 
globules  of  a  tin-white  color. 

Heated  in  a  matrass,  is  converted  into  vapor,  which  condenses 
in  the  neck  of  the  matrass  to  small  metallic  globules. 

Dissolves  readily  in  nitric  acid. 

Amalqam. 

e/ 

§  188.  Agllg2  and  Agllg3.  11=3—3.5.  G=10.5— 14.  Occurs 
crystallized  and  massive.  Color  and  streak  silver-white;  opaque. 

In  a  matrass,  boils,  gives  a  sublimate  of  metallic  mercury,  and 
leaves  a  spongy  residue  of  silver,  which  on  Ch  fuses  readily  to  a 
globule. 

Dissolves  readily  in  nitric  acid. 
Calomel  [Horn  Quicksilver], 

§  189.  Hg2Cl.  11=1—2.  G=0.48.  Occurs  usually  in  distinct 
crystals  or  crystalline  coats,  of  adamantine  lustre  and  yellowish- 
gray  color. 


BLOW-PIPE    ANALYSIS. 

In  a  matrass,  yields  a  white  sublimate  of  subchloride  of  mercury. 
Mixed  with  Sd  and  heated  in  a  matrass,  affords  globules  of  metallic 
mercury.  On  Ch,  completely  volatilized,  giving  a  white  Ct.  Shows 
the  chlorine-reaction  wrhen  treated  as  described  §  65. 

Treated  with  boiling  hydrochloric  acid,  is  partly  dissolved  and 
becomes  gray.  Not  affected  by  nitric  acid,  dissolved  by  aqua  regia. 
With  a  solution  of  caustic  potassa,  becomes  black. 

Cinnabar. 

§  190.  HgS.  H=2 — 2.5.  G=8.9.  Color  various  shades  of  red, 
from  cochineal-red  to  dark  brownish-red.  Powder  always  bright- 
red.  It  occurs  in  very  small  flattened  crystals,  or  granularly  massive. 

Heated  in  a  matrass,  is  volatilized  and  condenses  to  a  black  sub 
limate,  which  by  friction  assumes  a  red  color.  Mixed  writh  Sd, 
yields  on  heating  globules  of  metallic  mercury.  In  an  open  glass 
tube,  is  partially  decomposed  into  metallic  mercury  and  sulphurous 
acid.  On  Ch  it  is,  when  pure,  wholly  volatilized. 

Nitric  acid  and  hydrochloric  acid  have  no  visible  effect  on  it. 
Aqua  regia  dissolves  it,  part  of  the  sulphur  being  precipitated. 
Insoluble  in  caustic  potassa. 

ORES  OF  XICKEL. 
Copper  Nickel. 

§  191.  Ni2  As  or  Ni1  (As.  Sb).  H=5— 5.5.  G=  7.3— 7.6. 
Usually  massive;  of  copper-red  color,  with  a  gray  tarnish,  and 
metallic  lustre ;  very  brittle. 

In  a  matrass,  affords  a  very  slight  sublimate  of  arsenous  acid. 
In  an  open  glass  tube,  yields  a  copious  sublimate  of  arsenous  acid, 
and  usually  a  little  sulphurous  acid ;  the  assay-piece  assumes  at  the 
same  time  a  yellowish-green  color  and  crumbles  to  powder.  On 
Ch,  emits  arsenical  fumes  and  fuses  to  a  white  and  brittle  globule 
which,  when  treated  with  Bx  in  RF1,  imparts  usually  to  the  flux 
the  colors  of  iron  and  cobalt.  Sometimes  a  faint  Ct  of  oxide  of 
lead  is  deposited  on  the  Ch. 

Dissolves  almost  completely  in  concentrated  nitric  acid;  the 
solution  has  a  green  color;  on  cooling  arsenous  acid  separatos. 
Readily  dissolved  by  aqua  regia. 


88  ELDERHORST'S  MANUAL  OF 

Nickel  Glance  [Gersdorffite]. 

§  102.  (Ni,Fe)  +  (S2,As).  H=5.5.  G=5.6— 6.9.  Of  silver- 
white  or  steel-gray  color,  and  metallic  lustre. 

In  a  matrass,  decrepitates  violently  and  yields  a  yellowish-brown 
sublimate  of  sulphide  of  arsenic.  In  an  open  glass  tube,  emits 
arsenous  acid  and  sulphurous  acid.  On  Ch,  fuses  with  emission  of 
sulphur  and  arsenical  fumes  to  a  globule  which,  when  treated  with 
Bx  in  RF1,  gives  the  reactions  of  iron  and  cobalt.  After  having 
removed  these  two  metals,  the  remaining  globule  exhibits  with  the 
fluxes  the  reactions  of  pure  oxide  of  nickel. 

Partly  dissolved  by  nitric  acid,  sulphur  and  arsenous  acid  being 
precipitated. 

NicJceliferous  Gray  Antimony  [Ullmannite]. 

§  193.  NiS2-f Ni(3b,As).  11=5—5.5.  0  =  6.2—6.5.  It  closely 
resembles  the  preceding  ore  in  its  physical  properties. 

In  a  matrass,  yields  a  slight  white  sublimate.  In  an  open  glass 
tube,  emits  copious  antimonial  fumes  and  sulphurous  acid.  On  Ch 
in  RF1,  fuses  to  a  globule,  and  coats  the  Ch  with  antimonious  acid; 
sometimes  the  odor  of  arsenic  is  observable.  The  melting  globule, 
when  treated  with  Bx,  frequently  exhibits  the  reactions  of  iron  and 
cobalt  besides  those  of  nickel. 

It  is  violently  acted  upon  by  concentrated  nitric  acid,  sulphur, 
antimonious  and  arsenous  acids  being  precipitated.      Aqua  regia 
dissolves  it,  excepting  the  sulphur,  to  a  green  liquid. 
Capillary  Pyrites  [Millerite]. 

§  194.  NiS.  11=3—3.5.  0=5.2—5.6.  Occurs  usually  in  delicate 
capillary  crystals  of  brass-yellow  color  and  metallic  lustre. 

In  an  open  glass  tube,  evolves  sulphurous  acid.  On  Ch,  fuses 
with  emission  of  sparks  to  a  metallic  globule  which  is  attracted  by 
the  magnet.  The  calcined  mineral  gives  with  fluxes  the  indications, 
of  oxide  of  nickel,  and  sometimes  also  those  of  oxide  of  cobalt. 

By  heated  concentrated  nitric  acid  it  is  but  little  affected,  but  its 
color  is  changed  to  gray.  By  aqua  regia  it  is  wholly  dissolved. 

Emerald  Nickel. 

§195.  (NiO.C02+4HO)  +  2(NiO.HO).  11=3—3.2.  0=2.5—2.7. 
Usually  forms  incrustations  of  emerald-green  color,  and  vitreous 
lustre. 


BLOW-PIPE  ANALYSIS.  89 

In.  a  matrass,  loses  already  at  212°  a  considerable  amount  of 
water,  and  blackens.  In  Bx  and  SPh,  dissolves  with  effervescence, 
exhibiting  the  characteristic  nickel-reactions. 

Dissolves  easily  in  heated  dilute  hydrochloric  acid  with  effer 
vescence. 

Annabergite  [Nickel  Green].  » 

§  196.  3NiO.As05-f8HO.  Soft,  In  capillary  crystals,  also  mas 
sive  and  disseminated.  Color  fine  apple-green. 

In  a  matrass,  yields  water  and  darkens  in  color.  In  the  forceps, 
fuses  and  colors  the  outer  flame  light-blue.  On  Ch  in  RF1,  fuses 
with  emission  of  arsenical  vapor  to  a  blackish-gray  globule;  when 
treated  with  Bx  the  globule  gives  the  reactions  of  nickel,  some 
times  also  those  of  iron  and  cobalt. 

Soluble  in  acids. 

ORES  OF  SILVER. 

Native  Silver. 

§  197.  Pure  silver,  associated  with  gold,  copper,  arsenic,  iron, 
and  other  metals.  H=2.5— S.  G=10— 11.  Color  silver-white  ; 
lustre  metallic ;  ductile  and  malleable.  Occurs  usually  in  twisted 
filaments,  or  arborescent ;  sometimes  in  plates  or  massive. 

On  Ch,  fuses  easily  to  a  globule,  which  assumes  a  bright  surface, 
and  shows  after  cooling  a  silver-white  color.  Foreign  metals  are 
detected  by  the  methods  given  §§  103-105. 

It  dissolves  nitric  acid. 

Antimonial  Silver  [Discrasite]. 

§  198.  Ag6Sb  and  Ag4Sb.  11=3.5 — 4.  G=9.4— 9.8.  Occurs 
crystallized  or  massive,  granular.  Lustre  metallic;  color  and  streak 
silver-wrhite. 

On  Ch,  fuses  readily  to  a  gray  non-ductile  globule  and  coats  the 
Ch  writh  oxide  of  antimony ;  with  continued  heat  the  globule  as 
sumes  the  appearance  of  pure  silver,  and  the  Ct  becomes  reddish. 

Dissolves  in  nitric  acid,  leaving  a  residue  of  oxide  of  antimony. 

Horn  Silver  [Kerargyrite] . 

§  199.  Ag  Cl.  H=  1—1.5.  G=5.5.  Remarkable  for  its  pearl- 
gray  or  greenish  color,  its  semi-transparency,  resinous  lusCre,  and 
8* 


90  ELDERIIORST'S    MANUAL  OF 

more  especially  for  its  softness,  which  is  so  great  as  to  allow  it  to 
be  marked  by  the  nail.  It  turns  brown  on  exposure  to  air.  When 
rubbed  with  a  moistened  plate  of  zinc  or  iron  the  latter  becomes 
covered  with  a  coating  of  silver. 

It  fuses  in  a  candle-flame.  On  Ch,  is  easily  reduced,  especially 
when  mixed  with  Sd.  Mixed  with  oxide  of  copper  and  heated  on 
Ch  in  RF1,  chloride  of  copper  is  formed,  which  colors  the  flame 
azure-blue  (v.  §  G5). 

Insoluble  in  water  and  nitric  acid.  Slowly  soluble  in  caustic 
ammonia.  Partially  decomposed  by  a  boiling  solution  of  caustic 
potassa. 

Ernbolite  [Chloro-bromide  of  Silver.] 

§200.  2AgBr+3AgCl.  11=1—1.5.  G=5.3— 5.4.  Crystallized 
or  massive.  Lustre  resinous;  color  various  shades  of  green. 

On  Ch,  fuses  readily,  evolves  pungent  vapors  of  bromine,  and 
affords  a  globule  of  metallic  silver.  With  Sd  on  Ch,  reduced;  on 
dissolving  in  water  the  alkaline  mass  which  has  passed  into  the 
coal,  evaporating  the  solution  to  dryncss,  and  treating  the  residue 
with  bisulphate  of  potassa  as  described  §  63,  bromine-vapors  are 
given  out.  Fused  with  oxide  of  copper  on  Ch  in  RF1,  colors  the 
outer  flame  greenish,  then  blue  (v.  §  65). 

Bromyrite  [Bromic  Silver]. 

§  201.  Ag  Br.  11=1—2.  0  =  5.8—6.  Occurs  usually  in  small 
concretions.  Lustre  splendent;  color  yellowish-green  or  green. 
Sectile. 

Its  action  before  the  Blp  not  known;  behaves  probably  like  the 
preceding. 

Only  slightly  affected  by  acids.  Dissolves  in  heated  concentrated 
ammonia. 

loci  y  rite  [lodic  Silver]. 

§  202.  Agl.  Soft.  G=5.5.  Occurs  crystallized  or  in  thin  plates 
with  a  lamellar  structure.  Color  citron-yellow  to  yellowish-green. 

On  Ch,  fuses  readily,  colors  the  flame  purple-red,  and  affords  a 
globule  of  silver. 

Silver  Glance. 

§  203.  AgS.  11=2— 2.5.    G=7.    Color  blackish  lead-gray ;  lustre 


BLOW-PIPE    ANALYSIS.  91 

metallic.  It  is  easily  distinguished  from  other  minerals  of  the  same 
color  by  being  cut  by  a  knife  like  lead. 

On  Ch  in  OF1,  intumesces,  gives  out  sulphurous  acid,  and  finally 
yields  a  globule  of  metallic  silver. 

Soluble  in  dilute  nitric  acid,  leaving  a  residue  of  sulphur. 

Ruby  Silver  [Pyrargyrite.     Dark-red  Silver  Ore]. 

§  204.  3AgS,  SbS3.  H=2— 2.5.  G=5. 7-5.9.  Color  dark-red 
to  black,  giving  a  cochineal-red  powder.  Crystallizes  in  hexagonal 
prisms. 

In  a  matrass,  fuses  very  readily  and  yields  with  continued  heat 
a  sublimate  of  tersulphide  of  antimony.  In  an  open  glass  tube 
gives  antimonial  fumes  and  sulphurous  acid.  On  Ch,  fuses  readily 
and  deposits  a  Ct  of  antimonious  acid,  being  converted  into  sul 
phide  of  silver;  if  for  a  long  time  exposed  to  the  OF1  or,  when 
mixed  with  Sd,  to  the  RF1,  affords  a  globule  of  metallic  silver. 

Part  of  the  SbS3  is  sometimes  substituted  by  AsS3;  it  then  gives 
out  arsenical  fumes  when  mixed  with  Sd  and  heated  in  the  R  Fl 
on  Ch. 

The  pulverized  mineral,  when  heated  with  nitric  acid,  turns  black 
and  is  ultimately  dissolved,  leaving  a  residue  of  sulphur  and  anti 
monious  acid.  Caustic  potassa  also  blackens  it  and  effects  partial 
solution,  from  which  acids  precipitates  tersulphide  of  antimony. 

Proust  lie  [Light- red  Silver  Ore]. 

§  205.  3AgS,  AsS3.  11=2—2.5.  G= 5.4— 5.5.  Ycry  much  re 
sembles  the  dark-red  silver  ore,  but  is  of  a  somewhat  lighter  color. 

Before  the  Blp  and  to  solvents,  behaves  like  the  preceding, 
excepting  it  gives  off  arsenical  fumes  instead  of  antimonious  acid. 
The  solution  in  caustic  potassa  deposits  a  yellow  precipitate  when 
neutralized  with  acids. 

Brittle  Silver  Ore  [Stephanite]. 

§  206.  6  AgS,  SbS3.  H=2— 2.5.  G=6.2.  Of  metallic  lustre  and 
iron-black  color;  it  is  very  brittle  and  fragile,  and  its  powder  black. 

In  a  matrass,  decrepitates,  then  fuses  and  ultimately  yields  a  faint 
sublimate  of  tersulphide  of  antimony.  On  Ch,  fuses  very  readily 
and  coats  the  Ch  with  antimonious  acid.  If  the  blast  with  the  O 
Fl  is  kept  up  for  a  sufficient  time,  the  Ct  assumes  a  red  color  and  a 


92  ELDERUORST'S  MANUAL  OF 

globule  of  metallic  silver  is  obtained.  Contains  frequently  copper 
and  iron,  which  may  be  detected  by  the  process  described  §  71.  If 
arsenic  is  present  it  gives  in  the  open  tube  a  crystalline  sublimate 
of  arsenous  acid. 

In  dilute  heated  nitric  acid  it  dissolves,  excepting  the  sulphur 
and  antimonious  acid;  the  solution  becomes  milky  on  addition  of 
water.  Partially  dissolved  by  a  boiling  solution  of  caustic  potassa. 

fblybasite. 

§207.  9  (Cu2S,  AgS)  (SbS3,  AsS3).  11=2—3.  G=G.2.  Occurs 
usually  in  short  tabular  prisms,  or  massive.  Lustre  metallic ;  color 
and  streak  iron-black. 

In  a  matrass,  fuses  very  readily,  but  gives  nothing  volatile.  In 
an  open  tuboj  gives  sulphurous  acid  and  antimonial  fumes;  the  sub 
limate  contains  sometimes  crystals  of  arsenous  acid.  On  Ch,  gives 
a  Ct  of  oxide  of  antimony;  with  continued  heat,  gives  a  bright 
metallic  globule,  which,  on  cooling,  becomes  black  on  its  surface; 
sometimes  a  faint  Ct  of  oxide  of  zinc  is  deposited ;  the  metallic  glo 
bule  affords  with  fluxes  the  reaction  of  silver  and  copper. 

With  acids  behaves  like  bournonite. 
Stromeyerite  [Argentiferous  Sulphide  of  Copper]. 

§  208.  Cu2S.  -f  AgS.  11=2.5—3.  G=6.2— 6.3.  Occurs  usually 
in  small  compact  masses.  Lustre  metallic  ;  color  dark  steel-gray. 

In  a  matrass,  fuses  easily  and  gives  sometimes  a  little  sulphur. 
In  an  open  tube,  fuses  to  a  globule  and  gives  sulphurous  acid.  On 
Ch,  fuses  to  a  gray  metallic  globule  which  is  a  little  malleable  ; 
with  fluxes  the  globule  gives  the  reactions  of  copper,  sometimes 
also  those  of  iron ;  on  a  cupel  with  lead  affords  a  globule  of  silver. 

Dissolves  in  nitric  acid,  leaving  a  residue  of  sulphur. 

ORES  OF  TIN. 

Tin  Ore  [Cassiterite]. 

§  209.  SnO2.  11  =  6—7.  G=  6.3— 7.1.  It  occurs  crystallized  in 
square  prisms  terminated  by  more  or  less  complicated  pyramids; 
reentrant  angles  are  so  frequent  that  they  are  to  a  certain  extent 
characteristic ;  also  massive,  and  in  small  mammillated  masses  of 
fibrous  texture,  hence  called  "  wood  tin."  Color  very  various,  but 


BLOW-PIPE    ANALYSIS.  93 

usually  brown  or  black.     The  crystals  commonly  possess  a  very 
brilliant  lustre. 

Infusible  in  the  forceps ;  the  behavior  before  the  Blp  is  that  of 
pure  oxide  of  tin  (v.  Table  II,  22),  excepting  of  its  sometimes 
imparting  to  the  Bx  bead  a  slight  yellowish  tinge,  owing  to  the 
presence  of  iron,  and  exhibiting  the  reaction  for  manganese  when 
fused  with  soda  and  nitre  on  platinum-foil. 

Insoluble  in  acids.     Fused  with  caustic  potassa,  yields  a  mass 
which  is  mostly  soluble  in  water. 
Tin  Pyrites. 

§  210.  2  Cu2S,  SnS2  +  2  (FeS,  ZnS),  SnS2.  H=4.  G=4.3— 4.5. 
Of  steel-gray  or  iron-black  color,  and  metallic  lustre.  Occurs 
usually  massive,  granular,  and  disseminated. 

In  an  open  glass  tube,  yields  sulphurous  acid  and  oxide  of  tin, 
which  collects  close  to  the  assay-piece  and  which  cannot  be  vola 
tilized  by  heat.  On  Ch  in  R  Fl,  fuses  to  a  black  scoriaceous  glo 
bule  ;  in  0  Fl,  gives  out  sulphurous  acid  and  becomes  covered  with 
oxide  of  tin.  When  well  calcined  by  the  alternate  application  of 
0  Fl  and  R  Fl,  gives  with  Bx  the  indications  of  Fe  and  Cu.  With 
Sd  and  Bx,  yields  a  globule  of  impure  copper. 

Decomposed  by  nitric  acid  ;  a  blue  solution  is  obtained,  and  a 
mixture  of  sulphur  and  oxide  of  tin  remains  undissolved. 

ORES  OP  ZINC. 

Red  Zinc  Ore  [Zincite]. 

§  211.  ZnO,  containing  some  Mu203.  11=4—4.5.  G  =  5.4— 5.5. 
Of  a  deep-red  color  and  high  lustre  ;  of  distinctly  foliated  structure. 

Infusible  alone.  Dissolved  by  Bx  in  0  Fl  with  manganese 
reaction.  With  Sd  on  Ch,  deposits  a  copious  Ct  of  oxide  of  zinc. 

Soluble  in  nitric  acid  without  effervescence  ;  in  hydrochloric  acid 
'with  evolution  of  chlorine. 

Blende. 

§212.  ZnS.  H=3.5— 4.  0=3.9—4.2.  Of  very  variable  color, 
from  yellow  to  black;  of  resinous  lustre  and  lamellar  aspect,  dis 
tinctly  cleavable.  It  occurs  often  crystallized  in  rhomboidal  dodec 
ahedrons.  The  powder  is  always  light-colored,  white  or  grayish, 
and  dull. 


94  ELDERHORST'S  MANUAL  OF 

In  a  matrass,  sometimes  decrepitates  violently,  but  gives  nothing 
volatile ;  its  color  also  remains  unchanged,  excepting  the  green 
varieties,  which  become  yellow.  Strongly  heated  in  an  open  glass 
tube,  sulphurous  acid  is  evolved,  and  the  color  of  the  calcined  assay 
is  white,  yellowish,  or  brownish,  according  to  the  amount  of  FeS 
which  it  contains.  Alone,  infusible  or  only  rounded  at  the  thinnest 
edges.  On  Ch  in  R  Fl  a  feeble  dark  Ct  of  oxide  of  cadmium  is 
usually  obtained,  which  is  soon  followed  by  a  pure  zinc-Ct.  With 
Sd  on  Ch,  is  easily  reduced,  and  the  characteristic  zinc-flame  may 
frequently  be  observed.  Iron  is  readily  detected  by  calcining  the 
mineral  in  the  O  Fl  and  treating  the  residue  with  Bx. 

The  pulverized  mineral  dissolves  in  nitric  acid,  leaving  a  residue 
of  sulphur. 

&m  iilisan ite  [C alamine] . 

§  213.  ZnO.CO2.  11  =  5.  G  =  4— 4.5.  It  is  found  crystallized 
in  forms  derived  from  the  rhomboid.  Of  vitreous  lustre,  and  white, 
grayish,  or  brownish  color ;  semi-transparent  or  opaque.  Often 
stalactitic  or  mammillary. 

Heated  in  a  matrass,  loses  carbonic  acid  and,  if  pure,  appears 
after  cooling  enamel-white.  The  ZnO  is  often  to  a  large  extent 
substituted  by  FeO,  MnO,  CdO,  PbO,  MgO,  CaO  ;  it  then,  after 
cooling,  frequently  assumes  a  dark  color  and  gives  with  fluxes  the 
indications  of  iron  and  manganese.  Mixed  with  Sd  and  exposed 
to  the  II  Fl,  it  is  decomposed  and  oxide  of  zinc  deposited  on  the 
Ch.  If  the  temperature  was  raised  sufficiently  high,  a  zinc-flame 
is  sometimes  observable.  The  Ct  is  at  first  dark  yellow,  or  reddish 
when  cadmium  is  present. 

It  readily  dissolves  in  acids  with  effervescence ;  also  in  caustic 
potassa. 

Calamine. 

§  214.  3ZnO  +  Si03+  2110  or  2(3ZnO.Si03)  +  3HO.  11=4.5—5. 
G=3.1 — 3.9.  It  closely  resembles  in  its  plwsical  characters  the 
preceding  ore.  It  is  electric  by  heat;  the  smallest  fragment  heated 
attracts  light  substances. 

Infusible  in  the  forceps.  In  a  matrass  yields  water  and  turns 
milk-white.  Bx  dissolves  it  to  a  transparent  glass,  which  cannot 


BLOW-PIPE  ANALYSIS.  95 

be  made  opaque  by  flaming.  It  dissolves  in  S  Ph  to  a  transparent 
glass  which  becomes  opaque  on  cooling,  and  in  which,  when  highly 
saturated,  clouds  of  silica  are  observable  while  hot.  With  Sd  on 
Ch,  swells  and  affords  with  difficulty  a  Ct  of  oxide  of  zinc.  With 
SoCo,  assumes  a  green  color,  which,  when  the  heat  is  raised,  passes 
into  a  fine  light-blue  on  the  fused  edges. 

It  is  readily  decomposed  by  acids,  with  separation  of  gelatinous 
silicic  acid.     Partly  dissolved  by  caustic  potassa. 


APPENDIX. 

FOSSIL  FUEL. 

Anthracite. 

§  215.  C,  with  a  small  percentage  of  SiO3,  AFO3,  and  Fe'O3. 
H=2 — 2.5.  G=1.3 — 1.8.  Lustre  bright,  often  sub-metallic ;  color 
iron-black,  frequently  iridescent.  Fracture  conchoidal. 

In  a  matrass,  gives  usually  a  little  water,  but  no  empyreumatic 
oil.  Heated  on  platinum  foil  in  0  Fl,  is  slowly  consumed  without 
flame,  leaving  a  small  quantity  of  ash,  which  consists  of  SiO3, 
APO3,  and  more  or  less  Fe203.  Does  not  color  a  boiling  solution 
of  caustic  potassa. 

Bituminous  Coal  [Common  Coal]. 

§  216.  C,  H,  0,  in  variable  proportions;  the  bituminous  matter 
contains  from  76  to  90  per  cent,  of  carbon;  the  earthy  impurities 
consist  principally  of  SiO3,  AFO3,  and  CaO ;  contains  frequently  a 
small  amount  of  N  and  FeS2.  Softer  than  anthracite,  G=1.2 — 1.5. 
Less  highly  lustrous  than  the  preceding,  and  of  a  more  purely 
black  or  brownish-black  color. 

In  a  matrass,  some  varieties  soften  and  cake  {caking  coal),  while 
others  are  entirely  infusible ;  all  varieties  are  decomposed,  evolve 
combustible  gases  and  empyreumatic  oils,  and  leave  a  residue  of 
more  or  less  metallic  lustre  (coke),  which  behaves  like  anthracite. 
On  platinum  foil,  burns  with  a  luminous  flame  and  emission  of 
smoke,  leaving  an  earthy  residue. 


96  ELDERIIORST'S  MANUAL  OF 

Boiled  with  a  solution  of  caustic  potassa,  or  with  ether,  imparts 
to  these  solvents  no,  or  only  a  pale-yellow,  color. 

Brown  Coal. 

§  217.  Composition  the  same  as  that  of  bituminous  coal,  but 
the  organic  constituents  contain  only  from  GO  to  75  per  cent,  of 
carbon.  In  physical  proportion  bears  sometimes  a  close  resemblance 
to  the  preceding ;  some  varieties  show  distinctly  the  texture  of 
wood  (lignite). 

In  a  matrass,  infusible,  but  some  varieties  soften ;  evolves  com 
bustible  gases,  empyrcumatic  oils,  water  of  acid  reaction,  and  a 
peculiar  disagreeable  odor,  leaving  a  residue  which  consists  of 
carbon  and  a  considerable  amount  of  ash.  On  platinum  foil,  burns 
with  a  smoky  flame  and  emission  of  a  peculiar  odor. 

Boiled  with  a  solution  of  caustic  potassa,  colors  the  liquid  brown. 

Asplialtum. 

§  218.  C,  H,  O,  in  variable  proportions,  with  about  75  per  cent, 
of  carbon.  G=l — 1.2.  Of  black  or  brownish-black  color,  and 
bituminous  odor. 

Fuses  at  about  100°  C,  and  burns  with  a  bright  flame  and  emission 
of  a  thick  smoke,  leaving  little  ash,  which  consists  essentially  of 
SiO3,  APO3,  and  Fe'203.  In  a  matrass,  gives  empyrcumatic  oil, 
some  ammoniacal  water,  combustible  gases,  and  leaves  a  carbona 
ceous  residue. 

Treated  with  boiling  ether,  colors  the  solvent  wine-red  to  brown 
ish-red  (distinction  from  bituminous  coal);  treated  with  a  boiling 
solution  of  caustic  potassa,  does  not  color  the  liquid,  or  imparts  at 
the  most  a  pale-yellow  color  (distinction  from  brown-coal). 


BLOW-PIPE    ANALYSIS.  97 


FIFTH    CHAPTEE 

SYSTEMATIC    METHOD    FOR    THE    DISCRIMINATION    OF    INORGANIC 

COMPOUNDS. 

THE  careful  observer,  having  become  well  acquainted  with  the 
reactions  which  are  exhibited  by  the  metallic  oxides  and  other 
simple  compounds,  when  subjected  to  the  various  treatments 
detailed  in  the  second  chapter,  will  find  no  difficulty  in  ascertaining 
the  nature  of  any  mineral  substance  presented  to  him  for  analysis. 

If  the  reactions  are  not  quite  distinct,  owing  to  an  intermixture 
with  other  substances,  he  may  call  to  his  aid  the  processes  laid 
down  in  the  third  chapter,  which  will  enable  him,  in  most  cases,  to> 
detect  also  the  nature  of  the  impurities.  But  in  order  to  attain 
satisfactory  results  in  this  way,  a  certain  familiarity  with  all  th.- 
principal  tests  is  a  necessary  condition;  this  once  acquired,  any 
further  directions  are  quite  superfluous. 

Those,  however,  who  have  not  devoted  much  time  to  blow-pipe 
operations,  will  sometimes  experience  some  difficulties  in  drawing 
the  correct  conclusions  from  the  observed  phenomena,  a  difficulty 
which  is  to  a  great  extent  obviated  by  pursuing  the  course  given 
below.  This  methodical  course  has  the  advantage  of  giving  the 
operator  the  answer  to  every  phenomenon  which  he  observes,  and 
thus  leading  him,  though  sometimes  by  a  very  tortuous  path,  to  the 
right  solution.  An  example  will  show  this  more  clearly,  and  teach 
at  the  same  time  the  use  of  the  table. 

Suppose  a  substance  be  given  for  analysis.  The  operator  com 
mences  writh  No.  1.  The  substance  is  heated  in  R  Fl  on  Ch:  a 
garlic  odor  is  disengaged;  proceed  to  No.  2.  Treated  with  Sd  on 
Ch  does  not  give  a  mass  which  exhibits  the  reaction  of  sulphur; 
proceed  to  No.  3.  The  substance  shows  no  metallic  aspect;  pro 
ceed  to  No.  131,  thence  to  No.  135.  It  is  not  wholly  volatilized, 
nor  does  it  exhibit  the  reaction  of  sulphur;  proceed  to  No.  137. 
9  G 


98  ELDERIIORST'S  MANUAL  OP 

Here  we  find  that  the  substance  must  either  be  an  arsenite  or  an 
arsenate  (which  of  the  two,  cannot  be  decided  by  the  Blp  alone), 
and  to  find  the  metal,  we  proceed  to  No.  102.  It  affords,  after  cal 
cination,  with  Sd  on  Ch  a  fusible  metallic  button ;  proceed  to  No.  103. 
The  button  is  oxidable  (because  on  being  heated  in  OF1,  becomes 
covered  with  a  black  coating  of  oxide);  proceed  to  No.  105.  The 
button  is  red  and  malleable  ;  the  metal  is  copper.  The  substance, 
therefore,  was  arsenite,  or  arsenate,  of  copper. 

The  chief  constituents  of  the  body  having  thus  been  ascertained, 
the  analyst  should  never  omit  to  test  the  correctness  of  the  result 
by  the  processes  laid  down  in  the  third  chapter.  In  the  example 
given  above,  he  should  verify  the  result  by  the  test  given  in  §  57 
for  arsenous  acid,  and  by  those  given  in  §§  11  and  14  for  copper. 
If  we  wish  to  examine  the  assay  also  for  the  presence  or  absence 
of  some  accessory  constituents,  we  must  always  have  recourse  to 
the  methods  detailed  in  Chapter  III.  For  example,  having  found 
the  body  under  trial  to  consist  essentially  of  sulphur  and  lead,  and 
it  appears  desirable  to  know,  \vhethcr  or  not  it  contains  any  silver, 
we  must  subject  it  to  the  treatment  described  §  103. 

i  On  Ch  (RF1)  with  or  without  Sd  disengages  a  garlic 

1  -j       odor 2 

(  Not 4 

i  With  Sd  (RF1)  on  Ch  yields  a  scoriaceous  mass  Avhich 

2  <       exhibits  the  sulphur-reaction  (§  101)... Sulph arsenide.  131 
(  Not '. 3 

o  j  Metallic  aspect Arsenide.     131 

{  Not Arsenite  and  Arsenate.     131 

I  On  Ch  (OF1)  disengages  sulphurous  acid,  and  exhibits 

4  •(       the  sulphur-reaction  (§  101) Sulphur  Confound.     125 

(  Not. 5 

(  On  Ch  disengages  the  odor  of  rotten  horse-radish 

5  <       ,Selenium  Compound.     136 

(  Not 6 

(  The  substance,  after  having  been  well  dried,  fuses  on 

6-|      red-hot  Ch 1 

Not...  11 


BLOW-PIPE    ANALYSIS.  99 

I  Treated  as  indicated  §  65  imparts  to  the  flame  an  azure- 

7  I      blue  or  green  color 8 

(  Not Nitrate.  102 

oj  The  color  is  azure-blue 9 

(  The  color  is  green 10 

(  Treated  as  indicated  §  63  disengages  deep  yellow  vapors. 

9-j       Bromate.  102 

(  Not Chlorate.  102 

(  Treated  as  indicated  §  63  disengages  deep  yellow  vapors. 

10  <       , Bromate.  102 

(  Yiolet  vapors . lodate.  102 

(  Treated  as  indicated  §  65  imparts  to  the  flame  an  azure- 

11  -j      blue  or  green  color. 12 

(  Not. 17 

f  Heated  in  a  matrass  with  bisulphate  of  potassa  and  a 

little  peroxide  of  manganese  disengages  violet  vapors. 

12  I      Iodide  and  lodate.     102 

Deep  yellow  vapors, Bromide  and  Bromate.     102 

I  Not 13 

I  Treated  as  indicated  §  77  exhibits  the  fluorine-reaction. 

13^' Fluoride.     102 

(  Not 14 

(  Treated  as  indicated  §  65  imparts  to  the  flame  an  azure- 

14-\       blue  color 15 

(  A  green  color 16 

C  Heated  writh  Sd  on  Ch  gives  a  mass  which,  when  mixed 

with  bisulphate  of  potassa  and  black  oxide  of  manga- 

15  -{      nese  and  heated  in  a  closed  tube,  evolves  a  deep  yellow 

gas Bromide.     102 

LNot Chloride  and  Chlorate.     102 

f  Heated  with  Sd  on  Ch  gives  a  mass  which,  when  mixed 
-  £  j       with  bisulphate  of  potassa  and  peroxide  of  manganese 

and  heated  in  a  closed  tube,  evolves  violet  vapors,  Iodide.     102 
[Deep  yellow  vapors Bromide.    ,102 


17 


Effervesces  with  hydrochloric  acid Carbonate.  102 

Not 18 

When  finely  powdered  and  heated  with  hydrochloric  acid, 

effervesces Carbonate.  102 

Not 19 


100  ELDERIIORST'S  MANUAL  OF 

(  When  finely  powdered  and  heated  with  concentrated  hy- 

19  -J      drochloric  acid,  gelatinizes  ......  ,  .............................  30 

(  Not  ...........................  .  ......................................  20 

i  Fused  with  Sd  on  Ch  yields  neither  a  metallic  globule 

20  •<       nor  a  Ct  .........................................................  21 

(  Yields  a  metallic  globule  or  a  Ct  ..............................  22 

(  Treated  as  indicated  §  61  colors  the  flame  yellowish- 

21  <       green  ....................................................  Borate.  102 

I  Not  ..................................................................  23 

The  scoriaceous  mass  is  heated  in  a  platinum  spoon  with 
a  drop  of  concentrated  sulphuric  acid,  then  alcohol 

22  -\      poured  on  it,  and  lighted.  The  flame  appears  yellowish- 

green,  .....................................................  Borate.  1  02 

[Not,  ..................................................................  23 

(  Treated  as  indicated  §  7T  exhibits  the  fluorine-reaction, 

23  <       .........................................................  Fluoride.  102 

(  Not  ..................................................................  24 

^  ,  j  Heated  with  Sd  on  Ch  yields  a  button  of  fused  metal,  25 

L4  I  Not  ..................................................................  27 

{Heated  on  Ch  alone  behaves  as  indicated  §  96  ;  yields 
with  Sd  on  Ch  a  soft  globule  ......  Phosphate  of  Lead. 

Not  ..................................................................  26 

(  The  scoriaceous  mass  treated  with  boracic  acid,  as  indicated 

26  •<       §  95,  exhibits  the  reaction  of  phosphoric  acid,  Phosphate.  102 
(  Not  ......  ...........................................................  28 

i  Treated  as  indicated   §  95  exhibits  the  reaction  of  phos- 

27  \      phoric  acid  .......................................  Phosphate.  102 

(  Not  ..................................................................  28 

With  Sd  on  Ch  yields  a  metallic  button  or  a  copious  Ct  31 


(  W 

I  N 


0 

8     Not 

f  Pulverized  and  fused  with  5  or  6  times  its  weight  of  Sd 
9Q  j       in  a  platinum  spoon,  yields  a  mass  which,  when  heated 

with  hydrochloric  acid,  gives  a  gelatinous  precipitate       30 
[Not  ..................................................................       31 

(  The  gelatinous  precipitate  placed,  while  still  moist,  on  a 
30  \      blade  of  iron  or  zinc,  becomes  blue  .........  Tungstate.     139 

Not  ...................................................................     140 


f  Metallic  aspect 


BLOW-PIPE  ANALYSIS: 


101 


(  Yields  on  Cb  a  malleable  and  fusible  metallic  button, 
32  -<      wbicb  is  not  oxidable  .........................................       33 

(  Not  ...................................................................       36 

oq  j  Yellow  button  ......................................................       34 

|  White  button  .......................................................       35 

(  With  Bx  on  platinum  wire  gives  a  bluish  glass  ............ 

34  <       .............................................  Gold  with  Copper. 

(  Not  ............................................................  Gold. 

(  With  Bx  on  platinum  wire  gives  a  bluish  glass  ............ 

35  <       ...........................................  Silver  with  Copper. 

(  Not  ..........................................................  Silver. 

(  With  Bx  on  platinum  wire  gives  a  glass  which  is  blue  in 

36-^      both  flames  .............................................  Cobalt. 

(  Not  ..................................................................       37 

Q7  f  Gives  with  Bx  the  reactions  of  oxide  of  copper  ............       38 

'{Not  ..................................................................        42 

QQ  f  Red  and  malleable  metallic  button  ...............  Copper. 

* 


OQ  (  Deposits  on  Ch  a  Ct,  yellow  while  hot,  white  when  cold       41 
|  Not.     A  yellowish,  brittle  alloy  .........  Copper  and  Tin. 

,-  (  Malleable,  yellow  or  reddish  alloy  ......  Copper  and  Zinc. 

\      White,  malleable  alloy  .............  Copper,  Zinc,  Nickel. 

42  -{  Yery  fusible  metallic  button  ....................................       48 

(  Deposits  on  Ch  a  Ct  .............................................       44 

43  A  No  Ct  deposited  on  Ch;  exhibits  the  reactions  of  tin  ____ 
(       ...............................................................  Tin. 

41  j  White  Ct,  very  volatile  ...............................  .  ..........       45 

*(  Not  ...................................................................        4;i 

(  Yields  on  Ch  a  brittle  globule,  which  exhibits  the  anti- 

45  <      mony  reactions  .....................................  Antimony. 

(  Not  ..................................................  Tellurium. 

(  Metallic  aspect,  or  powder  assuming  metallic  lustre  under 

46  •<       the  polishing  steel  ........................  .....................       47 

(  Not  ..............................................................  "....       50 

.,-  j  Infusible  and  inoxidable  ...........................  Platinum. 

'  |  Oxidable  ...........................................................       48 

,  a  j  With  Bx  in  OF1  an  amethyst-colored  glass,  Manganese. 

8(  Not  .............................  ."  .....................................       49 

9* 


*  j 


102  ELDERttOR'ST's    MANUAL   OP 

(After  having  been  oxidized,  exhibits  with  fluxes  the  iron- 
reactions  .................................................  Iron. 
After  having   been  oxidized,   exhibits  with    fluxes  the 
nickel-reactions  ............  ............................  Nickel. 

£Q  j  Yields  with  Sd  on  Oh  in  RF1  a  tin  globule,  Oxide  of  Tin. 

(  Not  ...................................................................       51 

i  With  Bx  on  platinum  wire  a  green  glass  in  both  flames, 
51  •<       ..................................................  Chromic  Iron. 

Not  ...................................................................       52 

Yields  with  Sd  on  platinum  foil  in  OF1  a  bluish-green  mass       53 
Not  ..................................................................       54 

(  Gives  with  Bx  or  SPh  on  platinum  wire  an  amethyst- 
53  •<       colored  bead  ........................  Oxide  of  Manganese. 

(  Not.    Brown  powder,  Tungstate  of  Iron  and  Manganese. 

C  With  S  Ph  on  platinum  wire  in  RF1  gives  a  glass  which, 

f-A  j       on  cooling,  becomes  brownish-red  and,  when  touched 

j       with  tin,  violet  red  ....................  Titaniferous  Iron. 

^Not;  exhibits  the  iron-reactions  ...............................       55 

f  Heated  in  a  closed  glass  tube,  yields  water;   powder 
55  <       yellow  ...............  Hydrate  of  Sesquioxide  of  Iron. 

(Yields  no  water  ...................................................       56 

~£  j  Magnetic;  powder  black  .....................  Magnetic  Iron. 

\  Not;  powder  red  .........................  Peroxide  of  Iron. 

-,_  j  Affords  with  Sd  on  Ch  in  RF1  a  fusible  metallic  button,       58 
°'  {  Not  ...................................................................       66 

The  button  is  malleable  and  inoxidable  ..........  ............       59 

Oxidable  button  ...................................................       60 

Yellow  button  .................................  Oxide,  of  Gold. 

White  button  ................................  Oxide  of  Silver. 

n  (  Button  with  Ct  ....................................................       61 

\  Malleable  button  without  Ct  ....................................       75 

f  The  Ct  is  white  and  very  volatile,  Oxide  of  Antimony. 

61  \  Not  ...................................................................       62 

(  The  Ct  is  yellow,  and  the  button  soft  ........................       63 

62  \  The  button  is  brittle  .........................  ................  .  .....       65 

(  A  very  small  quantity  affords  with  Bx  or  SPh  in  OF1  a 
63<|       green  glass  .............................  Chromate  of  Lead. 

\  Not  .....................................................  ............       64 


BLOW-PIPE    ANALYSIS.  103 

(  The  substance  is  yellow  or  reddish,  Protoxide  of  Lead. 
64r<  The  substance  is  red Minium. 

(  The  substance  is  brown Deutoxide  of  Lead. 

f  Affords  with  Bx  or  SPh  in  OF1  a  green  bead 

65<       Chromate  of  Bismuth. 

(Not Oxide  of  Bismuth. 

(  Treated  on  Ch  in  OF1  deposits  a  Ct,  or  vaporizes  com- 
66 1      pletely 67 

(Not 70 

The  Ct  is  white,  and  very  volatile... Oxide  of  Antimony. 

Not 68 

^0  (  The  Ct  is  brown Oxide  of  Cadmium. 

bo J  J 


^ 

{ 


69 

f  The  substance  is  red  or  yellow  and  affords,  when  heated 

in  a  closed  glass  tube,  metallic  mercury 

69  -j       Oxide  of  Mercury. 

I  The  substance  is  white,  becomes  yellow  on  heating,  and 
[      on  cooling  white  again Oxide  of  Zinc. 

(  Affords  with  Bx  a  bead  which  is  blue  in  both  flames 

70-]       Oxide  of  Cobalt. 

(  Not 71 

-<  j  The  Bx  bead  is  green  in  both  flames 72 


Not 77 


-~  j  Soluble  in  water 73 


Insoluble  in  water 74 


_o  j  The  substance  is  orange-red Bichromate  of  Potass  a. 

j  The  substance  is  yellow...  Chr ornate  of  Potassa  or  Soda. 

f  The  substance  is  of  semi-metallic  aspect  or  grayish-black 
-,  j       Chromic  Iron. 

j  The  substance  is  a  green  powder 

[      Sesquioxide  of  Chromium. 

7_  j  The  button  is  white Oxide  of  Tin. 

°  {  The  button  is  red 76 

-n  j  The  substance  is  red  or  brown  Siiboxide  of  Copper. 

\  The  substance  is  black Protoxide  of  Copper. 

(  The  bead  is  green  in  OF1,  and   becomes  reddish-brown 
3T7<      in  RF1 7ft 

(  Not 78 


104  ELDERIIORST'S  MANUAL  OF 

»Q  j  The  bead  is  amethyst-colored  inOFl 79 

80 


(  Gives  off  water  when  heated  in  a  glass  tube 

79  •<       Hydrated  Oxide  of  Manganese. 

(  Not Oxide  of  Manganese. 

o^v  j  Heated  alone  on  Ch  in  OF1  becomes  magnetic 55 

(  Not 81 

(  Exhibits  with  SPh  on  platinum  wire  the  uranium  rcac- 
81  •<       tions ..Oxide  of  Uranium. 

(  Not , 82 

OQ  (  Soluble  in  water,  exhibiting  alkaline  reaction 83 

(  Not 91 

r.0  j  Very  soluble 84 

(  But  little  soluble 88 

o  ,  j  Heated  on  platinum  wire,  fuses  readily  and  vaporizes...       85 

*(  Not 81 

o~  j  Heated  on  platinum  foil,  stains  it  dark-yellow Lithia. 

0  (  Not 86 

f  Heated  on  platinum  wire,  colors  the  flame  pale  violet 

J       Hydrate  of  Potassa. 

I  Reddish-yellow;  the  outer  flame  becomes  enlarged 

(_      Hydrate  of  Soda. 

f  Moistened  with  a  drop  of  hydrochloric  acid,  and  heated  on 

87  •<       platinum  wire,  colors  the  flame  pale-green Baryta. 

(  Purple Strontia. 

{Moistened  with  a  drop  of  hydrochloric  acid,  and  heated 
on  platinum  wire,  colors  the  flame  purple Strontia. 
Not 89 

^Q  j  Heated  with  SoCo,  assumes  a  flesh-color Magnesia. 

9  (  Not 90 

or.  (  Heated  alone,  becomes  very  luminous Lime. 

\  Not ;  colors  the  flame  pale-green Baryta. 

j  Heated  with  SoCo,  assumes  a  fine  blue  color.. ..Alumina. 

91  j  Not 92 

n  (  Heated  with  SoCo,  assumes  a  flesh-color Magnesia. 

92  1  Not 93 

(  Heated  with  SoCo,  assumes  a  green  color..  Oxide  of  Zinc. 

93|Not 94 


BLOW-PIPE  ANALYSIS.  105 

(  Affords  with  SPh  in  OF1  a  colorless  glass,  which  in  RF1 

94  •<       becomes  blue 95 

(  Not 97 

(  Heated  in  a  closed  glass  tube,  evolves  ammonia  and  be- 

95  -j      comes  blue  or  green Tungstate  of  Ammonia. 

(  Not 96 

gg  (  On  Ch  alone,  infusible Tungstic  Acid. 

\  Fusible Tungsfate  of  Potassa  or  Soda. 

07  j  Exhibits  with  SPh  the  reactions  of Molybdie  Acid. 

97 1  Not 98 

OQ  j  Exhibits  with  SPh  the  reactions  of  pure...  Titanic  Acid. 

8}Not 99 

(  Affords  with  SPh  in  RF1  a  reddish-yellow  glass;  the 

99  <      intensity  of  the  color  increases  on  cooling 100 

(Not 101 

The  glass,  when  heated  on  Ch  with  tin,  becomes  violet. 

Titanic  Acid,  containing  Iron. 

C  With  Sd  on  Ch  in  RF1,  affords  a  metallic  powder  attract- 

_.  ~.j  j      able  by  the  magnet Oxide  of  Nickel. 

I  Not:  affords  with  SPh  in  OF1  a  glass  which,  while  hot, 
L     is  red,  and  colorless  when  cold Oxide  of  Cerium. 

NITRATES,  CHLORATES,  BROMATES,  IODATES,  CARBONATES,  PHOS 
PHATES,  BORATES,  CHLORIDES,  BROMIDES,  IODIDES,  OXIDES, 
HYDRATES. 

1  ,0  j  Affords  with  Sd  on  Ch  in  RF1  a  fusible  metallic  button.     103 

-[Not 109 

-i/%o  j  The  button  is  malleable  and  inoxidable 104 

(  The  button  is  oxidable.  105 

(  The  button  is  yellow Salt  of  Gold. 

\  The  button  is  w^hite Salt  of  Silver. 

-  (  The  button  is  red  and  malleable Salt  of  Copper. 

Not 106 

The  button  is  white  and  malleable  and  forms  no  Ct.... 

Salt  of  Tin. 

Not 10T 

Forms  a  w^hite  and  very  volatile  Ct...Salt  of  Antimony, 

The  Ct  is  orange-yellow 108 


106  ELDERHORST'S  MANUAL  OF 

JQ«  (  The  button  is  malleable , Salt  of  Lead. 

\  The  button  is  brittle Salt  of  Bismuth. 

1AQ  j  Treated  with  Sd  on  Ch  in  RF1,  deposits  a  Ct 110 

y|  Not 112 

n  j  The  Ct  is  white  and  very  volatile.... Salt  of  Antimony. 

U{  Not .". Ill 

(  The  Ct  is  reddish-brown Salt  of  Cadmium. 

Ill  K  The  Ct  is  yellow  while  hot,  and  white  when  cold 

(       ". Salt  of  Zinc. 

C  On  Ch  alone,  affords  a  gray  and  infusible  powder  which, 

J       under  the  polishing  steel,  assumes  metallic  lustre.... 

|       Salt  of  Platinum. 

LNot 113 

(  Heated  with  Sd  in  a  closed  glass  tube  affords  a  subli- 
113 -!  mate  of  mercury Salt  of  Mercury. 

(  Not .". .*..     114 

(  Heated  with  Sd  in  a  closed  glass  tube  disengages  am- 

1 14  <       monia Salt  of  Ammonia. 

(  Not 115 

(  Gives  with  13 x  or  SPh  beads  which  are  blue  in  both 

115  \       flames Salt  of  Cobalt. 

(  Not 

„  (  The  beads  are  screen  in  both  flames.. . . Salt  of  Chromium. 

6  I  Not - 117 

(  The  bead  exhibits  the  reactions  produced  by  oxide  of 

117  -I       copper Salt  of  Copper. 

(  Not 118 

(  Affords  with  Sd  on  Ch  a  metallic  powder,  which  assumes 

118  •<       lustre  by  friction,  and  is  attracted  by  the  magnet 119 

(  Not 120 

Q  j  Gives  with  Bx  in  KF1  a  bottle-green  glass.  Salt  of  Iron. 

(  Gives  with  Bx  in  RF1  a  grayish  glass....  Salt  of  Nickel. 

(  Gives  with  Bx  in  OF1  an  amethyst-colored  bead 

120-J  Salt  of  Manganese. 

(  Not 121 

f  Infusible  mass,  which  assumes,  with  SoCo,  previous  to 
1o-i  J  fusion,  a  fine  blue  color Salt  of  Alumina. 

I  A  flesh-color Salt  of  Magnesia. 

LNot 122 


BLOW-PIPE   ANALYSIS.  107 

(  The  watery  solution  gives  a  precipitate  on  addition  of 
122-  some  Sd 123 

(  Not 124 

T  Heated  on  platinum  wire,  colors  the  flame  pale-green... 
IOQ  j  Salt  of  Baryta. 

I  Colors  the  flame  purple Salt,  of  Strontia. 

LNot;  but  becomes  very  luminous Salt  of  Lime. 

(  Heated  on  platinum  wire,  colors  the  flame  violet  

124-J  Salt  of  Potassa. 

(  Colors  the  flame  reddish-yellow Salt  of  Soda. 


SULPHUR  COMPOUNDS. 


-  j  Metallic  aspect ;  sulphides 126 

Not 127 

The  substance  is  calcined,  and  the  metal  detected  by  pro 
ceeding  as  indicated  above,  beginning  with  No 102 

(  Sulphates,  hyposulphates,  sulphites,  hyposulphites,  sul- 

127  -j       phides  prepared  artificially  by  precipitation,  and  a  few 

(      native  sulphides 128 

f  Heated  with  hydrochloric  acid  disengages : 

128  J  Sulphuretted  hydrogen Sulphide.  130 

I  Sulphurous  acid 129 

^  Nothing Sulphate  or  Hyposulphate.  130 

(  Hydrochloric  acid  produces  a  white  precipitate  of  sul- 

129  <      phur Hyposulphite.  130 

(  Not Sulphite.  130 

130  <{  The  metal  is  detected,  beginning  with  No 102 


ARSENIC  COMPOUNDS. 

Metallic  aspect 132 

Not 135 

1QO  \  Readily  and  completely  volatilized  on  Ch 133 

L321  Not 134 

(  Gives  a  white  and  very  volatile  Ct 

133  <       Arsenide  of  Antimony. 

f  Not...  ...Arsenic. 


108  ELDERHORST'S  MANUAL  OP 

The  substance,  which  is  an  arsenide  or  sulpharsenide,. 
is  thoroughly  calcined,  and  then  the  metal  detected 

(       as  indicated  above,  beginning  with  No 102 

(  Wholly  volatilized  on  Ch,  and  exhibiting  the  reactions 

135-]      of  sulphur 136 

(  Not  wholly  volatilized,  or  exhibiting  no  sulphur-reaction ,     137 

-io/>(  The  substance  is  yellow Orpiment. 

\  The  substance  is  red Realgar. 

f  The  substance  is  very  volatile Arsenous  Acid. 

07  J  Not :  arsenite  or  arsenate.  The  substance  is  well  cal 
cined  with  alternating  OF1  and  RF1,  and  the  metal 
found,  beginning  with  No 102 

SELENIUM  COMPOUNDS. 

(  Metallic  aspect Selenide. 

138  -\  Not :  selenite  or   selenate ;  the  substance  is  well  cal- 

(      cined,  and  the  metal  detected,  beginning  with  No....     102 

TUNGSTATES. 

(  With  Sd  on  platinum  wire  in  OF1  affords  a  grcenish- 

139  •<      blue  mass Wolfram. 

(  Not 140 

(  Heated  with  Sd  in  a  closed  glass  tube,  evolves  am- 

14:0  •<       monia Tungstate  of  Ammonia. 

(  Not 141 

1  ,..  j  Soluble Tungstate  of  Potassa  or  Soda. 

(  Insoluble Tungstate  of  Lime,  Baryta,  &c. 

SILICATES. 

The  analogy  in  chemical  composition  and  properties, 
and  the  number  of  native  silicates,  make  it  impossible 
1A9J       ^°  discriminate  them  by  a  few  simple  tests.*     The 
'      base  or  bases  may,  however,  in  many  cases  be  de 
tected  by  proceeding  as  indicated  above,  beginning 
with  No 102 

*  For  the  discrimination  of  the  native  silicates,  v.  Chapter  VI. 


BLOW-PIPE    ANALYSIS.  109 


SIXTH   CHAPTER. 

ON  THE  DISCRIMINATION  OF  MINERALS  BY  MEANS   OF  TUE  BLOW 
PIPE,  AIDED  BY  HUMID  ANALYSIS. 

BY  the  methods  given  in  the  preceding  chapters,  we  can  readily 
detect  the  constituents  of  most  inorganic  compounds,  whether  pre 
pared  artificially  or  occurring  in  nature  ;  especially  if  heavy  metals 
form  the  principal  constituents.  But  these  methods  do  not  enable 
us  to  discriminate  the  different  native  silicates,  and  other  mineral 
bodies,  which  consist  essentially  of  such  substances  that  do  not 
show  any  very  characteristic  reactions  before  the  blow-pipe,  as  ex. 
gr.  the  alkaline  earths.  In  some  cases  we  may  succeed  in  ascer 
taining  the  principal  ingredients  of  the  substance  under  examina 
tion,  but  fail  in  establishing  the  mineral  species.  To  attain  this 
end  more  securely,  w^e  must  pursue  a  course,  composed  of  an  ex 
amination  of  the  physical  properties  of  the  body  and  of  blow-pipe 
operations,  aided  by  humid  analysis.  The  course  adopted  in  this 
"  Manual "  is  that  given  by  Franz  von  Kobell,  as  laid  down  in  his 
"  Tafeln  zur  Bestimmung  der  Miner  alien."  The  following  is  only 
an  extract,  slightly  modified,  from  this  treatise : 

The  minerals,  according  to  Yon  Kobell's  system,  are  arranged  in 
two  large  groups,  the  first  embracing  those  possessing  metallic 
lustre,  the  second  those  devoid  of  metallic  lustre.  To  avoid  mistakes, 
originating  in  the  fact  that  some  minerals  occur  sometimes  with, 
and  sometimes  without,  metallic  lustre,  these  minerals  will  be  found 
enumerated  in  both  groups. 

The  same  precaution  has  been  taken  in  regard  to  those  species 
in  which  degree  of  fusibility,  whether  below  or  above  5,  might  ap 
pear  doubtful.  The  degree  of  fusibility  is  to  be  judged  of  from  the 
following  scale  : 

1.  Gray  Antimony. — Fusible  in  coarse  splinters  in  the  flame  of  a 
candle. 

2.  Xatrolite. — Fusible  in  fine  splinters  in  the  flame  of  a  candle. 

10 


110  ELDERIIORST'S  MANUAL  OF 

3.  Almandine  or  Iron-Garnet. — Easily  fusible  before  the  blow 
pipe. 

4.  Actinolitc  (a  variety  of  hornblende). — Fusible  before  the  Blp 
in  coarse  splinters. 

5.  Orthoclase. — Fusible  before  the  Blp  in  fine  splinters. 
G.  Broncite. — Fusible  on  the  edges  in  very  fine  splinters. 

The  fusibility,  when  equal  to  that  of  actinolite,  is  designated  by 
4  ;  when  between  that  of  natrolite  and  almandine,  by  2,  5,  and  so  on. 

The  two  large  groups  are  divided  into  classes  according  to  the 
fusibility  ;  these  again  in  divisions,  &c.,  by  which  means  we  obtain 
the  following  general  classification: 

GROUP  I.   MINERALS  POSSESSING  A  METALLIC  LUSTRE. 
CLASS  I.  Native  malleable  metals,  and  mercury. 
CLASS  II.  Fusibility  1 — 5,  or  readily  volatile. 

Division  1.  Give  a  strong  arsenical  odor  on  Ch. 

Division  2.  Give  on  Ch,  or  in  an  open  tube,  the  horse-radish 
odor  of  selenium. 

Division  3.  Give  in  an  open  tube  a  white  or  grayish  sublimate, 
which  is  fusible  into  colorless  drops,  indicative  of 
tellurium. 

Division  4.  Give  antimonial  fumes  on  Ch. 

Division  5.  Give  with  Sd  on  Ch  a  sulphur-reaction,  but  do  not 
give  indications  as  above. 

Division  6.  Do  not  exhibit  the  properties  of  the  preceding  di 
visions. 
CLASS  III.  Infusible,  or  fusibility  above  5,  and  not  volatile. 

Division  1.  Give  with  Bx,  in  small  quantities,  the  manganese- 
reaction. 

Division  2.  Treated  on  Ch  in  RF1,  become  magnetic. 

Division  3.  Resembling  those  of  division  2. 

GROUP  II.  MINERALS  NOT  POSSESSING  METALLIC  LUSTRE. 

CLASS  I.  Easily  volatile,  or  combustible. 

CLASS  II.  Fusibility  1—5,  not,  or  only  partially,  volatile. 

Part  I.  Give  with  Sd  on  Ch  a  metallic  globule  or  magnetic 
metallic  mass. 


BLOW-PIPE    ANALYSIS.  Ill 

Division  1.  Give  with  Sd  a  globule  of  silver. 
Division  2.   Give  with  Sd  a  globule  of  lead. 
Division  3.  When  moistened  with  hydrochloric  acid,  color  the 
flame  blue,  and  give  with  nitric  acid  a  solution 
which,  on  addition  of  an  excess  of  ammonia,  as 
sumes  an  azure-blue  color. 
Section  1.  Give  on  Ch  a  strong  arsenical  odor. 
Section  2.  Give  no  arsenical  odor. 
Division  4.  Impart  to  the  Bx  bead  a  blue  color. 
Division  5.  When  fused  on  Ch  in  RF1,  give  a  black  or  gray 

metallic  magnetic  mass. 

Section  1.  Give  on  fusion  a  strong  arsenical  odor. 
Section  2.  Soluble  in  hydrochloric  acid  without  leaving  a  per 
ceptible  residue,  and  without  gelatinizing. 
Section  3.  With  hydrochloric  acid,  form  a  jelly,  or  are  decom 
posed  with  separation  of  silica. 
Section  4.  But  little  affected  by  acids. 

Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 
Part  II.  With  Sd  on  Ch,  give  no  metallic  globule,  or  magnetic 

metallic  mass. 

Division  1.  After  fusion  and  continued  heating  on  Ch  or  in  the 
forceps,  have  an  alkaline  reaction,  and  change  to 
blue  the  color  of  a  moistened  red  litmus-paper. 
Section  1.  Easily  and  completely  soluble  in  water. 
Section  2.  Insoluble  in  water,  or  soluble  with  difficulty. 
Division  2.  Soluble  in  hydrochloric  acid  without  leaving  a  per 
ceptible  residue,  some  also  soluble  in  water  ;  not 
gelatinizing. 

Division  3.  Soluble  in  hydrochloric  acid,  forming  a  perfect  jelly. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  4.  Soluble  in  hydrochloric  acid  with  separation  of  silica, 

without  forming  a  perfect  jelly. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  5.  Little  aifected  by  hydrochloric  acid  ;  imparting  to  the 
Bx  bead  the  color  of  manganese. 


112  ELDERIIORST'S  MANUAL  OF 

Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 
CLASS  III.  Infusible,  or  fusibility  above  5. 

Division    1.    After   ignition   moistened  with    SoCo   and   again 

ignited,  assume  a  bright-blue  color. 
Section  1.  Giving  much  water  in  a  matrass. 
Section  2.  Giving  little  or  no  water  in  a  matrass. 
Division  2.  Moistened  with  SoCo  and  ignited,  assume  a  green 

color. 

Division  3,  After  ignition  have  an  alkaline  reaction,  and  turn 
into  blue  the  color  of  a  moistened  red  litmus-paper. 
Division  4.   Completely  soluble,  or  nearly  so,  in  hydrochloric  or 
nitric  acid,  without  gelatinizing  or  leaving  a  per 
ceptible  residue  of  silica. 

Division  5.  With  hydrochloric  acid,  form  a  jelly  or  arc  decom 
posed  with  separation  of  silica. 
Section  1.  Giving  water  in  a  matrass. 
Section  2.  Giving  traces,  or  no  water  in  a  matrass. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 
Section  1.  Hardness  below  T. 
Section  2.  Hardncss=T,  or  above. 

GROUP  I.    MINERALS  POSSESSING  A  METALLIC  LUSTRE. 

CLASS  I.  NATIVE  MALLEABLE  METALS,  AND  MERCURY. 
Native  silver,  see  §  19T. 
Native  Gold  and  Electrum   (alloy  of  silver  and 

gold),  see  §  150. 
Native  copper,  see  §  134. 
Native  Lead,  characterized  by  coating  on  charcoal 

(see  §  23)  and  softness;  11  =  1.5. 
Native  Platinum,  see  §  152. 
Native  Palladium,  distinguished  from  the  preceding 

by  being  soluble  in  nitric  acid. 
Native  Iron,  see  §  154. 
Native  Mercury,  see  §  187. 

CLASS  II.  FUSIBILITY  1  TO  5,  OR  READILY  VOLATILE. 
Division  1.   Give  a  strong  arsenical  odor  on  charcoal. 
Native  Arsenic,  see  §  118. 


BLOW-PIPE    ANALYSIS.  113 

Bufrenoysite,  see  §  110  ;  Tennantitc,  sec  §  139 ;  Po 
ly  basitc,  see  §  207 ;  Domeykite,  see  §  140. 

Smaltine,  see  §  128 ;  Cobaltine,  see  §  129. 

Copper  Nickel,  see  §  191 ;  Gersdorffite,  see  §  192 ; 
Chloanthite=XiAs,  resembles  the  preceding 
two ;  distinguished  from  copper  nickel  by  its 
tin-white  color,  and  from  gcrsdorffite  by  not 
giving  the  reactions  for  sulphur. 

Arsenical  Pyrites,  see  §  161. 

Division  2.  Give  on  charcoal,  or  in  an  open  tube,  the  horse 
radish  odor  of  selenium. 

Selenide  of  mercury  =HgSe2,  Onofrite  =  Hg  (S.Se) 
and  selcnide  of  mercury  and  lead  (Selenqueck- 
silberblei)=3PbSfe-f  HgSe,  yield  metallic  mer 
cury  on  being  heated  with  Sd  in  a  closed  glass 
tube  (§  91);  the  latter  yields  a  globule  of  me 
tallic  lead  on  being  heated  on  charcoal  with  Sd. 

Clausthalite=PbSe.  Color  lead-gray ;  volatile 
without  previous  fusion,  depositing  first  a  slight 
gray,  then  a  white,  and  finally  a  greenish-yellow 
coating ;  with  Sd  yields  with  difficulty  globules 
of  lead. 

Xaumannite=AgSe.  Color  iron-black;  melts 
readily  and  yields  with  Bx  a  globule  of  pure 
silver. 

Berzelianitc=Cu2Se  and  Eucairite  Cu2Se-fAgSe. 
Color  of  the  former  silver-white,  of  the  latter 
lead-gray.  Distinguished  from  the  other  min 
erals  of  this  division  by  giving  copper-reactions. 

Division  3.  Give  in  an  open  tube  a  white  or  grayish  sublimate, 
which  is  fusible  into  colorless  drops,  indicative 
of  tellurium,  see  §  11. 

The  assay-piece  used  for  this  experiment  ought  not 

to  be  very  small.     It  must  also  be  borne  in  mind 

that   the  minerals  of  this   division   frequently 

evolve  an  odor  of  selenium,  owing  to  a  small 

10*  H 


114  ELDERHORST'S  MANUAL  OF 

percentage  of  selenium  w.hich  they  contain  as 
adventitious  constituent. 

The  minerals  of  this  division  may  be  subdivided 
according  to  their  color. 

a.  Ores  of  tellurium  of  tin-white  or  silver-white 
color. 

Native  Tellurium,  fuses  readily  and  is  volatile  with 
out  leaving  a  residue. 

Hessite=AgTe,  and  Altaitc  =  PbTe  ;  both  soluble 
in  nitric  acid ;  the  former  yields  with  Sd  on  Ch 
a  globule  of  metallic  silver. 

Some  varieties  of  sylvanite,  see  §  151. 

b.  Ores  of  tellurium  of  lead-gray  or  steel-gray  color. 
Tetradymite,  see  §  123. 

Sylvanite,  see  §  151. 

Nagyagite=Pb,  Au,  Te,  S.  Color  blackish  lead-gray. 

Distinguished  from  the  preceding  by  its  solution 

in  nitric  acid  giving  a  copious  precipitate  with 

sulphuric  acid. 

Division  4.   Give  copious  antimonial  fumes  on  charcoal  (see  §  16). 

The  fumes  possess  sometimes  the  odor  of  sulphur 
ous  acid  or  arsenic. 

Native  Antimony,  distinguished  by  its  tin-white 
color;  Stibnitc,  see  §  115;  Zinkenite,  see  §  170; 
Jamesonite,  see  §  170;  Bournonite,  see  §  170. 

The    powrdercd    stibnite,   on   being    heated  with 

"  hydrate  of  potassa,  assumes  a  yellow  color, 
while  the  latter  three  minerals,  which  are  steel- 
gray,  do  not  change  color.  Bournonite,  on  being 
treated  with  nitric  acid,  imparts  to  the  solution^ 
a  sky-blue  color,  and  gives  copper-reactions  on 
being  treated  as  described  in  §  71.  Zinkenite 
and  Jamesonite  are  converted  into  white  powders 
by  treatment  with  nitric  acid  without  imparting 
a  color  to  the  acid ;  they  are  distinguished  by 
their  hardness,  that  of  zinkenite  being =3. 5,  that 
of  jamesonite=2.5. 


BLOW-PIPE  ANALYSIS.  115 

Closely  resembling  the  above  in  their  chemical 
behavior  are  the  following  rare  minerals :  Plu- 
mosite,  see  §  170  ;  Boulangerite,  see  §  120  ;  Geo- 
kronite,  see  §  170  ;  Plagionite,  see  §  170;  Kilbri- 
kenite;  Steinmannite. 

Discrasite,  see  §  198 ;  Stephanite,  see  §  206;  Polyte- 
lite=S,  Sb,  Zn,  Fe,  Ag,  Cu ;  some  varieties  of 
Tetrahedrite,  see  §  138  ;  Miargyrite =AgS,  SbS3. 
Discrasite  does  not  give  a  sulphur-reaction,  all 
the  others  do.  Polytelite  gives  a  copper-reac 
tion  on  being  treated  as  described  in  §  73. 
Miargyrite,  streak  dark  cherry-red;  stephanite, 
streak  black.  Miargyrite  and  stephanite,  hard- 
ness=2.5;  Polytelite,  hardness=3.5.  All  the 
minerals  of  this  subdivision  give  a  globule  of  sil 
ver  on  being  treated  as  described  §  104  or  §  105. 

Wolfsbergite  (antimonial  copper) = Cu'S,  SbS3 ;  does 
not  give  a  globule  of  silver,  but  yields  a  globule 
of  metallic  copper  on  being  treated  with  Sd  on 
charcoal. 

Ullmannite,  see  §  193;  Berthierite,  see  §  116; 
Breithauptite=Ni  Sb.  All  yield  a  magnetic 
globule  with  continued  heat.  Breithauptite  is 
distinguished  from  the  other  two  by  not  giving 
a  sulphur-reaction. 

Division<$.  Give  with  Sd  on  Ch  a  sulphur-reaction,  but  do  not 
give  the  general  reactions  of  the  preceding 
divisions. 

Silver  Glance,  §  503. 

Galena,  see  §  169. 

Cinnabar,  see  §  90. 

Manganblende=MnS.  Color  iron-black,  streak 
green.  The  pulverized  mineral  evolves  sulpha, 
retted  hydrogen  with  hydrochloric  acid. 

Hauerite  —  MnS2.  Color  brownish-black,  streak 
brownish-red.  Yields  sulphur  on  being  heated 
in  a  matrass. 


116  ELDERHORST'S  MANUAL  OF 

Copper  Glance,  sec  §  131;  Stromeyerite,  see  §  208; 
Tin  Pyrites,  see  §  210;  Copper  Pyrites,  see 
§  135;  Purple  Copper,  see  §  136;  Cuban=Cu2S, 
Fe2S3;  Wittichite=3Cu2S,  BiS3;  Aikinite  (acicu- 
lar  bismuth)=3Cu2S,  BiS3-f  2(3PbS,BiS3);  Gru 
nauite  =BiS3+10Ni2S3 ;  Cuproplumbite=Cu2S, 
2PbS.  All  these  minerals  are  partially  soluble 
in  nitric  acid,  the  solution  possessing  a  sky-blue 
or  green  color;  on  addition  of  water  to  the  con 
centrated  solution  a  white  precipitate  is  produced, 
if  the  mineral  under  examination  was  wittichitc, 
grunauite,  or  aikinite.  [To  distinguish  these 
three,  add  to  the  acid  solution  sulphuric  acid: 
a  precipitate  indicates  aikinite;  wittichite  gives 
the  copper-reaction  on  being  treated  as  described 
in  §  73,  grunauite  not.]  Copper  pyrites  and 
cuban  are  distinguished  from  the  others  by  their 
brass-yellow  color;  purple  copper  is  also  charac 
terized  by  its  color.  To  distinguish  the  re 
maining  four  minerals,  make  a  solution  in  nitric 
acid;  add  sulphuric  acid:  a  precipitate  indicates 
cuproplumbite ;  if  no  precipitate  is  produced, 
add  hydrochloric  acid:  a  precipitate  indicates 
Stromeyerite;  to  distinguish  between  copper- 
glance  and  tin  pyrites,  see  §  137  and  §  210. 

Millerite,  see  §  194;  Linnseitc,  see  §  130;  Iron 
Pyrites,  see  §  158;  Marcasitc,  see  §  159;  Stcrn- 
bergite=S,  Ag,  Fe.  The  members  of  this  sub 
division  fuse  to  globules  which  are  attracted  by 
the  magnet.  They  are  readily  distinguished  by 
the  characteristics  given  in  Chapter  III.  Stcrn- 
bergite,  by  the  treatment  described  in  §  104, 
yields  a  globule  of  silver.  Marcasite  and  iron 
pyrites  can  only  be  distinguished  by  their  crys 
talline  form. 

Bismuthine,  see  §  125. 


BLOW-PIPE    ANALYSIS.  117 

Division  6.  Do  not  exhibit  the  properties  of  the  preceding  divisions. 

Amalgam,  see  §  188. 

Native  Bismuth,  see  §  122. 

Hematite,  see  §  156. 

Magnetite,  see  §  157. 

Wolfram=MnO,FeO,Wo3.  Color  dark  grayish  or 
brownish-black.  Fusibility=3.  The  pulverized 
mineral  on  being  boiled  with  aqua  regia  assumes 
gradually  a  yellowish  color. 

Samarskite=Nb03,  FeO,  U203,  YO.  Color  velvet- 
black.  Fusibility  =4.  By  fusing  tl*?  pulverized 
mineral  with  hydrate  of  potassa,  boiling  the 
fused  mass  with  hydrochloric  acid,  filtering,  and 
concentrating  the  solution  by  boiling  with  addi 
tion  of  tin  foil:  the  liquid  assumes  a  fine  blue 
color  which  does  not  pass  into  red  on  addition  of 
water  (as  is  the  case  with  compounds  containing 
titanium),  but  becomes  paler  and  gradually  dis 
appears. 

Rhodonite,  dark  varieties=3MnO.Si03,  3HO. 
Yields  water  on  being  heated  in  a  matrass. 
Soluble  in  hydrochloric  acid  with  separation  of 
silica. 

Some  varieties  of  psilomelane,  see  §  183. 

Lievrite  and  Allanite,  some  varieties,  see  p.  123 

Plattnerite=Pb02.  Color  iron-black;  easily  re 
duced  to  metallic  lead. 

Red  Copper,  some  varieties,  see  §  142. 
CLASS  III.  INFUSIBLE,  OR  FUSIBILITY  ABOVE  5. 
Division  1.  Give  with  borax,  in  small  quantities,  the  manganese 
reactions. 

The  members  of  this  division  are  distinguished  from 
each  otherprincipally  by  their  physical  properties. 

Braunite,  see  §  182;  Hausmannite,  see  §  181;  Psilo 
melane,  see  §  183;  Pyrolusite,  see  §  180;  Frank- 
Unite,  some  varieties,  see  §  186;  Manganite= 
Mn203,  HO.  Color  steel-gray  to  iron-black ;  streak 


118  ELDERIIORST'S  MANUAL  OF 

dark  reddish-brown ;  hardness  3 — 4 ;  yields  water 
in  a  matrass. 

Division  2.  Heated  on  charcoal  in  reduction-flame,  become  mag 
netic. 

Hematite,  see  §  156. 

Franklinite,  see  §  18G;  Magnetite,  see  §  157. 

Titaniferous  iron,  see  §  162  ;  some  varieties  of  Rutil 
and  Arkansite  (see  below);  some  varieties  of 
Limonitc  (§  155),  and  Blende  (§  212). 
Division  3.  Minerals  resembling  those  of  Division  2. 

Chromic  Iron,  see  §  127. 

Molybdenite=MoS2 ;  Graphite=C.  Both  very  soft, 
hardness=  1.5.  Molybdenite,  when  heated  in  the 
forceps,  colors  the  flame  greenish;  and  gives  a 
sulphur-reaction  when  treated  as  described  in 
§107. 

Arkansite=Ti02;  Perofskite=CaO.Ti02.  Both 
give  the  reaction  for  titanium  as  described  §  111. 
Distinguished  by  crystalline  form. 

Iridosmine,  see  §  153. 

Tantalite  and  Columbite==MnO,  FeO,  TaO3,  NbO3, 
WO3,  SnO2;  Yttro-tantalite==3(CaO.YO.FeO), 
(TaO3,  WO3).  The  color  of  these  minerals  is 
iron-black;  yttro-tantalite  loses  its  color  before 
the  Blp  and  becomes  yellowish  or  white,  that  of 
the  others  remains  unchanged.  Acids  affect 
them  but  little.  Tantalite  and  columbite  give 
the  same  reaction  as  samarskite  when  treated 
with  hydrate  of  potassa,  &c.  (See  p.  117.) 

Pitchblende.  Color  usually  velvet-black,  lustre 
greasy;  partially  soluble  in  nitric  acid  to  a  yel 
low  liquid ;  the  solution  gives  a  sulphur-yellow 
precipitate  with  ammonia. 

GROUP  II.  MINERALS  NOT  POSSESSING  METALLIC  LUSTRE. 
CLASS  I.  EASILY  VOLATILE  OR  COMBUSTIBLE. 

Native  Sulphur.  Completely  volatile,  burns  with 
a  blue  flame  and  emission  of  sulphurous  acid. 


BLOW-PIPE    ANALYSIS. 


119 


Realgar,  see  §  119;  Orpiment,  see  §  120. 

Arsenolitc,  see  §  121. 

Red  Antimony,  see  §  117;  Valentinite=Sb03.  Color 
white;  does  not  change  color  with  hydrate  of 
potassa;  does  not  evolve  sulphuretted  hydrogen 
with  hydrochloric  acid. 

Sal-ammoniac=NH4Cl ;  Mascagnine=NH3,S03-}- 
2HO.  Color  white;  both  evolve  ammonia  with 
hydrate  of  potassa;  the  former  is  volatile  with 
out  previous  fusion,  the  latter  intumesces. 

Cinnabar,  see  §  190;  Calomel,  see  §  189. 

CLASS  II.  FUSIBILITY  1 — 5;  NOT,  OR  ONLY  PARTIALLY,  VOLATILE. 
Part  I.  Give  with  carbonate  of  soda  on  charcoal  a  metallic 

globule  or  a  magnetic  metallic  mass. 
Division  1.   Give  with  carbonate  of  soda  a  globule  of  silver. 

Proustite,  see  §  205 ;  Ruby  Silver,  see  §  204 ;  Xan- 
thocone=3AgS,  AsS5-f  2(3 AgS,  AsS3),  behaves 
like  proustite,  from  which  it  is  distinguished  by 
its  yellow  streak. 

Horn  Silver,  see  §  199;  lodyrite,  see  §  202. 

Selbite=AgO,  CO2,  dissolves  in  nitric  acid  with 

effervescence. 
Division  2.  Give  with  carbonate  of  soda  a  globule  of  lead. 

The  minerals  of  this  division  are  all  soluble  in 
nitric  acid ;  the  solution  gives  a  copious  pre 
cipitate  with  sulphuric  acid. 

Mimetlne  =  PbCl  +  3  (3PbO,  AsO5) ;  Hedyphane= 
PbCl-f  3(3[PbO.CaO],  [As05.P05]).  ^The  for 
mer  completely,  the  latter  partially  reduced  to 
metallic  lead  with  evolution  of  arsenical  fumes. 

Pyromorphite,  see  §  175. 

Minium,  see  §  168 ;  Crocoisite,  see  §  171 ;  Mclano- 
chroite  =  3PbO,2Cr03.  Aneoxene=V03,  AsO5, 
PbO,  ZnO.  Crocoisite  and  melanochroite  give 
the  chromium-reaction  (§  67).  The  latter  three, 
on  being  boiled  with  hydrochloric  acid,  give  an 
emerald-green  solution  ;  on  adding  alcohol  to  the 


120  ELDERIIORST'S  MANUAL  or 

liquid,  concentrating  by  heat,  pouring  off  from 
the  residue,  and  then  adding  water :  the  liquid 
assumes  a  sky-blue  color  if  the  mineral  was 
arseoxene. 

Linarite=PbO.S03-fCuO.HO  is  characterized  by 
its  deep  azure-blue  color. 

Cerusite,  see  §  172  ;  Cerasine,  sec  §  111 ;  Lead- 
hillite,  see  §173;  Lanarkite  =  PbO.C02-f  PbO. 
SO3.  All  soluble  in  nitric  acid  with  efferves 
cence  ;  leadhillite  and  lanarkite  leave  an  insolu 
ble  residue  of  sulphate  of  lead.  The  solution  of 
cerasine  gives  with  nitrate  of  silver  a  precipitate 
of  chloride  of  silver. 

Mendipite  =  PbCl+2PbO  ;  Matlockite=PbCl-f  Pb 
0.  Dissolve  in  nitric  acid  without  effervescence ; 
the  solution  gives  a  precipitate  with  nitrate  of 
silver. 

Anglesite,  see  §  174. 

Wulfenitc,  sec  §  129. 

Scheeletine=PbO,W03.  Color  yellow,  yellowish- 
brown,  lustre-  resinous.  Soluble  in  abundant 
quantity  of  hydrochloric  acid,  leaving  a  yellowish- 
green  residue  (WO3).  With  sulphuric  acid  the 
pulverized  mineral  assumes  a  bright  lemon- 
yellow  color. 

Yauquelinite,  see  §  118;  Vanadinite=2  PbO,  TO3 
with  PbCl-f  2PbO.  Color  of  the  former  blackish- 
green,  olive-green ;  of  the  latter  brown,  yellowish. 
Both  impart  to  the  borax-bead  an  emerald-green 
color.  Both  are  soluble  in  nitric  acid  ;  the  solu 
tion  of  vanadinite  is  yellow  and  gives  a  precipi 
tate  with  nitrate  of  silver.  That  of  vauquelinite 
not. 

Division  3.  When  moistened  with  hydrochloric  acid,  color  the 
flame  blue  ;  and  give  with  nitric  acid  a  solution 
which,  on  addition  of  an  excess  of  ammonia,  as 
sumes  an  azure-blue  color. 


BLOW-PIPE    ANALYSIS.  121 

Section  1.  Give  on  charcoal  a  strong  arsenical  odor. 

Olivenite,  see  §  14t. 

Tyrolite,  see  §  148  ;  Chalcophyllite=8CuO.As05+ 
23HO.  Color  green.  Both  decrepitate  violently 
and  yield  much  water ;  chalcophyllite  dissolves 
in  ammonia  without  leaving  a  residue. 

Liroconite=As05,P05,CuO,A103,HO.  Color  sky- 
blue.  Does  not  decrepitate  ;  loses  22  per  cent, 
of  water  on  ignition. 

Euchroite  =  4CuO.  AsO5  -f  7HO  ;  Erinite  =  5CuO. 
As05-f2HO.     Color'of  both  emerald-green.  The 
former  loses  by  ignition  18^  per  cent,  of  water, 
the  latter  only  5  per  cent. 
Section  2.  Do  not  give  an  arsenical  odor  on  charcoal. 

Atakamite,  see  §  141. 

Cyanosite,  see  §145;  Brochantite  =  3CuO.S03  + 
3HO  ;  Covelline=CuS.  These  three  minerals 
give  a  sulphur-reaction  (§  107);  cyanosite  is  solu-' 
ble  in  water,  the  other  two  not.  Color  of  covel- 
line  dark  indigo-blue,  of  brochantite  emerald- 
green. 

Red  Copper,  see  §  142  ;  Melaconite=CuO  ;  Teno- 
rite=CuO.  The  color  of  the  latter  two  is  dark 
steel-gray  to  black.  All  three  dissolve  readily 
in  acids  without  effervescence  (except  impure 
varieties  of  melaconite). 

Malachite,  see  §  143;  Azurite,  see  §  144;  Mysorin 
=  CuO.C02.  Color  blackish-brown;  does  not 
yield  water  in  a  matrass.  All  three  dissolve 
readily  in  acids  with  effervescence. 

Phosphocalcite,  see  §  146  ;  Libethenite=4CuO.P05 
+  HO;  Ehlite=5CuO.P05+3HO;  Tagilite=4 
CuO.P05+  3HO.  Are  all  readily  soluble  in 
nitric  acid  without  effervescence;  the  (slightly 
acid)  solution  gives  a  precipitate  with  acetate 
of  lead.  Phosphocalcite  loses  14  per  cent,  of 
water  on  ignition,  the  others  less  (from  7 — 
11 


122 


ELDERIIORST  S    MANUAL  OF 


Libethenite  is  dark  olive-green ;  ehlite  and  tagi- 
lite  emerald-green. 

Chalcolite=3CuO,  TO5  +  2(U203,  PO5)  -f  24  HO. 
Color  emerald-green.  Dissolves  in  nitric  acid  to 
a  yellowish-green  liquid;  on  addition  of  ammonia 
in  excess,  a  bluish-green  precipitate  is  formed, 
the  supernatant  liquid  being  blue. 
Division  4.  Impart  to  the  borax-bead  a  blue  color. 

Erythrinc,  see  §  131 ;  Annabergitc,  see  §  196. 
Division  5.    When  fused  on  charcoal  in  reduction- flame,  give  a 
black  metallic  magnetic  mass. 

To  observe  well  the  magnetic  character  of  the  fused 
mineral,  it  is  advisable  to  expose  a  pretty  large 
assay-piece  to  the  action  of  the  reduction-flame. 
Section  1.  Evolve  a  strong  arsenical  odor  on  being  fused. 

Scorodite,  see  §  166  ;  Pitticite=Fe203,  As05-f  HO ; 
Beudantitc  =  3  FcO.As05+3  Fe203,  2  As05-f  18 
HO.  The  pulverized  minerals  assume  with  hy 
drate  of  potassa  a  reddish-brown  color.  Scoro 
dite  and  beudantite  occur  crystallized ;  pitticito 
massive,  rcniform. 

Arseniosidcrite  =  5CaO,  AsO3  -f  3(2FeO,  AsO5)  -f  1 1 
HO.  Color  yellowish-brown ;  fibrous ;  lustre  silky. 

Pyromeline=:NiO,  SO3,  HO,  AsO5.  Partly  soluble 
in  water ;  the  solution  assumes  a  blue  color  on 
addition  of  ammonia. 

Section  2.  Soluble  in  hydrochloric  acid  without  leaving  a  per 
ceptible  residue,  and  without  gelatinizing. 

Green  Vitriol,  see  §  164;  Botryogen=3FeO,  2S03 
-f  3(Fe203,2S03)-f  36IIO.  Are  soluble  in  water; 
botryogen  leaves  an  ochreous  residue.  A  similar 
behavior  show  Copiapitc=2Fe203,  5S03+18IIO 
(color  yellow),  and  Coquimbite=Fe203,  3S03-f 
9HO,  color  white. 

Spathic  Iron,  see  §  163. 

Hureaiilitc=3(5MnO,2P05)  +  5FeO,2P05+30IIO; 
Triplite=4MnO.P05+4FeO.P05.  Fuse  readily; 


BLOW-PIPE  ANALYSIS.  123 

moistened  with  sulphuric  acid  give  the  phos 
phoric  acid  reaction  (§  35) ;  with  borax  strong 
manganese-reaction  ;  hureaulite  yields  much 
water,  triplite  none  or  very  little. 

Triphiline=3  LiO,  P05+6(3[FeO,  MnO],  PO5) 
shows  a  similar  behavior ;  the  manganese-reac 
tion  is  less  decided.  On  dissolving  the  mineral 
in  hydrochloric  acid,  evaporating  the  solution  to 
dryness,  adding  alcohol,  heating  the  alcohol  to 
ebullition  and  burning  the  vapor,  the  flame  as 
sumes  a  purple  color. 

Yivianite,  see  §  165;  Anglarite=4  FeO.P05+4HO : 
Dufrenite=2  Fe203.P06+2^  HO;  Cacoxene=2 
FeO.P05-f  12HO.  Fuse  readily  and  behave 
with  sulphuric  acid  like  the  preceding  ;  give  no 
manganese-reaction.  Yield  much  water  in  a 
matrass :  cacoxene  33  per  cent. ;  vivianite  28  per 
cent. ;  anglarite  16  per  cent. ;  dufrenite  8^  per 
cent.  Color  of  anglarite  bluish-gray ;  of  dufrenite 
leek-green ;  of  cacoxene  ochre-yellow. 

Hematite,  see  §  156. 

Section  3.  With  hydrochloric  acid  form  a  jelly,  or  are  readily 
decomposed  with  separation  of  silica. 

Cronstedtite  =  3  (FeO.  MnO.  MgO),  SiO3  -f  Fe20  >, 
3HO.  Color  black;  streak  dark  leek-green; 
yields  water;  gelatinizes  with  hydrochloric  acid. 

Lievrite=3(3[FeO,  CaO],  Si03)-f  2(AP03,  Fe203), 
SiO3;  Allanite=3(CeO,  CaO),  Si03+2([Fe203, 
APO3],  SiO3).  Yield  no  water,  or  only  a  trace ; 
gelatinize  with  hydrochloric  acid;  allanite  fuses 
with  intumescence  to  a  voluminous  brownish  or 
blackish  glass ;  lievrite  intumesces  but  slightly, 
decrepitates  and  fuses  to  an  iron-black  bead. 
Hardness  of  allanite=6,  of  lievrite=5 — 6. 
Pyrosmalite==Fe2CP-fFe203,6HO+4([3FeO,2Si03] 
-f  [3  MnO,  2  SiO3]).  Does  not  gelatinize;  fusi 
bility  =2;  gives  the  chlorine-reaction  (§  65). 


124  ELDERIIORST'S  MANUAL  OF 

Allochroite[lime-iron-garnet]=3CaO,Si03+Fe203, 
SiO3.  Gelatinizes  imperfectly ;  fuses  readily;  dis 
tinguished  from  the  preceding  by  absence  of 
cleavage. 

Hismgerite  =  (3FeO,Fe208),  Si03+xIIO;   Xylotile 
[a  variety  of  serpentine].     Fuse  with  difficulty;' 
do  not  gelatinize.     The  former  is  black,  amor 
phous;  the  latter  brown,  fibrous,  woody.     Both 
yield  water  in  a  matrass. 

Some  impure  varieties  of  Limonite,  see  §  155. 
Section  4,  But  little  affected  by  acids. 

Crocidolite=3(NaO,MgO),4Si03  +  3(3FeO,2Si03) 
-fxHO ;  Arfvedsonite=:NaO,Si03-f  3FeO,2Si03. 
Fusibility=l.T — 2.  Color  of  crocidolite  lavender- 
blue  or  leek-green,  fibrous,  yields  water  in  a  mat 
rass  ;  arfvedsonite  is  black  and  yields  no  water. 

[See  also  Hornblende  and  Tourmaline,  below,  some 
varieties  of  which  become  slightly  magnetic  after 
fusion.] 

Green  Earth  [a  variety  of  pyroxene].  Fusibility 
=  3;  color  celandine-green;  hardness=l;  earthy. 

Acmite=NaO.Si03-f  Fe2O3,2Si03;  Hedenbergite  [a 
black  pyroxene]=3Ca0.2Si03-f  3Fe0.2Si03.  Fu 
sibility  of  the  former=2,  of  the  latter=2.6;  form 
a  black  lustrous  slag.  Both  are  cleavable. 

Almandinc[iron-garnet]=3FeO.Si03+AF03.Si03. 
Fusibility=3;  hardness=7 — 7.5.  Color  red,  red 
dish-brown.  Not  cleavable. 

Rhodonite,  some  varieties;  see  below. 

Lepidolite,  some  varieties;  see  below. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 

Molybdine  =  Mo03.  Color  sulphur-yellow;  earthy. 
Gives  with  the  fluxes  the  reactions  of  molybdic 
acid.  Dissolves  readily  in  hydrochloric  acid ; 
the  solution  is  colorless,  but  turns  blue  on  being 
stirred  with  an  iron  spatula. 

Eulytine=2  BiO3,  3  SiOs  with  some  phosphate  and 


BLOW-PIPE    ANALYSIS.  125 

fluoride  of  iron.  Gelatinizes  with  hydrochloric 
acid.  On  charcoal  yields  a  globule  of  metallic 
bismuth. 

Bismutite,  see  §  124. 
Part  II.  With  carbonate  of  soda  on  charcoal,  give  no  metallic 

globule  or  magnetic  metallic  mass. 

Division  1.  After  fusion  and  continued  heating  on  charcoal  or 
in  the  forceps,  have  an  alkaline  reaction,  and 
change  to  blue  the  color  of  a  moistened  red  lit 
mus-paper. 
Section  1.  Keadily  and  completely  soluble  in  water. 

Nitre=KO.N05;  Nitratipe=NaO.N05.  Deflagrate: 
vividly  on  burning  coals.  Fused  on  platina  wire, 
the  former  colors  the  flames  bluish  with  a  red 
tint;  the  latter  bright-yellow. 

Xatron=NaO.C02-f  10HO ;  Trona=2XaO.3C02-f 
4HO.  The  watery  solution  has  an  alkaline  reac 
tion,  and  effervesces  on  addition  of  hydrochloric 
acid. 

Glauber  Salt=XaO.  S03  +  10HO;  Thenardite= 
NaO.SO8;  Glaserite=KO.S03;  Epsomite=MgO. 
S03+7HO;  Potash  Alum=KO.S03-f  A1202.3S03 
-f  24HO.  The  watery  solutions  of  these  min 
erals  give  a  copious  precipitate  with  chloride  of 
barium ;  the  solution  of  potash  alum  and  epsomite 
are  precipitated  by  carbonate  of  potassa  [distin 
guished  by  reaction  with  solution  of  cobalt,  §  44] ; 
the  concentrated  solution  of  glaserite  gives  a 
precipitate  with  bichloride  of  platina;  glauber 
salt  yields  much  water,  thenardite  none. 

Common  Salt=Na-Cl.  The  watery  solution  gives 
a  copious  precipitate  with  nitrate  of  silver. 
Gives  also  the  reactions  for  chlorine  described 
§§  65,  66. 

Borax=lSTa0.2B034-10IIO.      Gives   the   reaction 

for  boracic  acid,  §  60. 

Section  2.  Insoluble  in  water,  or  soluble  with  difficulty. 
11* 


126  ELDERIIORST'S  MANUAL  OF 

Gay-Lussite=CaO.C024-NaO.C02+6HO;  Whith 
crite=BaO.C02.  Dissolve  in  dilute  hydrochloric 
acid  with  effervescence  ;  the  former  yields  water, 
the  latter  not. 

Anhydrite=CaO.S03 ;  Gypsum=CaO.S03+2HO; 
Polyhalite  =  KO.SO3  +  MgO.SO3  -f  2(CaO.S03) 
+  2110  ;  Glauberite  =  NaO.SO3  -f  CaO.SO3. 
Soluble  in  much  hydrochloric  acid ;  in  the  solution 
chloride  of  barium  gives  a  precipitate.  Gypsum 
yields  much  water,  polyhalite  little,  the  rest 
none ;  anhydrite  is  distinguished  by  superior 
hardness=3.5  ;  polyhalite  is  distinguished  from 
glauberite  by  its  solution  giving  a  yellow  pre 
cipitate  with  bichloride  of  platina. 

Barytes=BaO.S03;  Celestine=SrO.S03.  Insoluble 
in  hydrochloric  acid ;  give  a  sulphur  reaction 
when  treated  as  described  §  107.  Celestine 
colors  the  flame  red,  §  34 ;  barytes  yellowish- 
green,  §  35. 

Fluor=CaF;  Cryolite=3NaF-f  APF3 ;  Pharma- 
colite=2CaO.As05+6IIO.  Do  not  effervesce 
with  acids,  and  give  no  sulphur  reaction. 
Pharmacolite  evolves-  arsenical  odor  on  charcoal ; 
the  other  two  give  fluorine  reaction,  §  76.  Fusi 
bility  of  fluor=3,  of  cryolite=l. 

Chiolite=3XaF-|-2Al2F3,  behaves  like  cryolite; 
occurs  only  massive  granular;  white  cryolite  is 
distinctly  crystalline  and  cleavable  in  3  directions. 
Division  2.  Soluble  in  hydrochloric  acid  without  leaving  a  per 
ceptible  residue ;  some  also  soluble  in  water ; 
not  gelatinizing. 

Ammonia  Alum  =  NIPO.  SO3  +  APOS.  3S03  -f 
24HO;  Goslarite=ZnO.S03+7HO.  Both  soluble 
in  water;  give  sulphur  reaction,  §  107.  Heated 
on  charcoal  and  treated  with  solution  of  cobalt, 
the  former  assumes  a  blue,  the  latter  a  green, 
color,  §§  44,  45. 


BLOW-PIPE    ANALYSIS. 


127 


Sassolin=B03,3HO  ;  Boracite=3MgO,4B03 ;  Hy- 
droboracite=3(CaO.MgO),4B03+18HO.  Give 
the  boracic  acid  reaction,  §  60.  Sassolin  is 
soluble  in  alcohol,  the  others  not ;  boracite  yields 
no  water,  while  the  others  do. 

Manganblende  and  Hauerite  give  strong  manga 
nese  reaction;  see  p.  115. 

Wagnerite=MgF+3MgO.P05;  Apatite  =  3(3CaO. 
PO5)  +  Ca(Cl,F).  Moistened  with  sulphuric  acid, 
impart  a  pale  bluish-green-color  to  the  flame. 
Fusibility  of  wagnerite=3 — 3.5  (with  intumes 
cence)  ;  of  apatite==5  (without  intumescence) ; 
wagnerite  is  soluble  in  dilute  sulphuric  acid  ; 
apatite  not. 

Amblygonite  =  LiO,  NaO,  APO3,  PO5,  F.  Fusi 
bility  =2;  hardness=6.  With  difficulty  soluble 
in  concentrated  sulphuric  or  hydrochloric  acid. 

Uranite  =  SCaO.PO5  -f  2(3U203.P05)  +  24. HO. 

Fuses    readily,    yields   water,    and   gives   with 

fluxes  the  reactions  of  sesquioxide  of  uranium. 

See  Table  II. 

Division  3.    Soluble  in  hydrochloric  acid,  forming  a  perfect 

jelly. 
Section  1.  Give  water  in  a  matrass. 

Datholite  =  3(CaO.B03)  -f  3Ca0.4Si03  -f  3  HO. 
Yields  but  little  water,  and  gives  the  boracic 
acid  reaction,  §  60. 

Natrolite=NaO.Si03+AP03.Si03-f2HO.  Fusi- 
bility=2,  does  not  intumesce ;  hardness  =  5 — 5.5. 

Scolecite= CaO.  SiO3 -f  APO3. SiO3 +  3HO ;  Laumon- 
tite  =  3CaO.  2Si03  +  3(AP03.  2Si03)  -f  12HO. 
Scolecite,  on  being  heated,  curls  up  like  a  worm 
and  finally  melts  to  a  bulky,  shining  slag,  which 
in  the  inner  flame  becomes  a  vesicular  slightly 
translucent  bead;  hardness=5.5.  Laumontite 
intumesces  and  fuses  to  a  white  translucent 
enamel ;  hardnesses. 


128  ELDERIIORST'S  MANUAL  or 

Nearly  related  to  scolccite  and  showing  a  similar 
behavior,  are  Mcsolite  and  Thomsonite. 

Phillipsite  ==  (CaO,KO).Si03  +  APOlSiO3  -f  5HO. 
Fusibility =3,  with  slight  intumescence;  occurs 
usually  in  twin  crystals. 
Section  2.    Giving  only  traces  or  no  water  in  a  matrass. 

Helvin=MnO,  MnS  +  2  (MnO.  BeO.  FeO),  SiO3; 
Tephroite=3MnO.Si03.  Distinguished  from  the 
other  minerals  of  this  section  by  giving  man 
ganese-reactions.  Color  of  helvin  wax-yellow, 
hardncss=6 — G.5;  of  tcphroitc  ash-gray,  hard- 
ness=5.5 — G. 

Hauyne  and  Lapis  Lasuli—SiO^APO3,  CaO,  KG, 
S03,S,  are  of  azure-blue  color;  give  sulphur-reac 
tion,  §  10T.  Fusibility  of  the  former=4.5,  of 
the  latter=3. 

Nosean  and  Skolopsite=Si03,  A1203,  CaO,  NaO, 
SO3,  of  gray  or  brownish  color;  give  sulphur- 
reaction,  §  107.  Fusibility  of  nosean=4.5;  of 
skolopsite=3  (with  intumescence  like  idocrase). 

Sodalite  =  NaCl  -f  3  NaO.  Si03+ 3  (APO3,  SiO3); 
Eudialyte=Si03,  ZrO3,  CaO,  XaO,  FeO,  01,  give 
the  chlorine-reaction,  §  65.  The  former  fuses 
to  a  transparent  colorless  glass,  the  latter  to  a 
grayish-green  scoria  or  opaque  glass. 

Wollastonite=3CaO,  SiO3.  The  hydrochloric  acid 
solution  gives  no,  or  only  a  very  slight,  precipi 
tate  with  ammonia. 

Eukolite=Si03,  NbO3,  ZrO3,  CaO,  XaO.  By 
boiling  the  hydrochloric  acid  solution  with  tin, 
it  assumes  a  fine  blue  color  on  reaching  a  certain 
degree  of  concentration.  See  also  Wohlerite. 

Nepheline=2  (NaO.KO),  SiO3  +  2  (APO3,  SiO3); 
Meionite=3CaO.  Si03  +  2  (APO3,  SiO3);  Melli- 
lite  =  2  (3  [CaO.  MgO.NaO],  SiO3)  -f  (APO3. 
Fe203),  SiO3.  The  hydrochloric  acid  solution  is 


BLOW-PIPE    ANALYSIS.  129 

precipitated  by  ammonia.     Meionite  fuses  with 
intumescence,  the  others  quietly. 

Division  4.  Soluble  in  hydrochloric  acid  with   separation   of 
silica,  without  forming  a  perfect  jelly.     (It  is 
sometimes  necessary  to  treat  the  finely  pulverized 
mineral  with  concentrated  acid.) 
Section   1.  Giving  water  in  a  matrass. 

Apophyllite  =  K0.2Si03-f  8(CaQ.Si03)  -f  16HO ; 
Pectolite=3([NaO.  KO].  SiO3)  -f  4(3CaO.  2Si03) 
+  3  HO;  Okenite==3CaO,4Si03-f  6HO.  The 
silica  separates  in  the  shape  of  gelatinous  lumps. 
The  hydrochloric  acid  solution  gives  no,  or  onlv 
a  slight,  precipitate  with-  ammonia.  Pectolite 
yields  but  little  water,  the  others  much.  Fusi 
bility  of  apophyllite=1.5,  forming,  a  white  ve 
sicular  glass;  of  okenite=2.5 — 3,  forming  a 
porcelain-like  mass. 

Analcime=3  Na0.2Si03.  -f  3(Al203,2Si03)+6H(X 
Gelatinizes  like  the  preceding;  in  the  acid  solu 
tion  ammonia  produces  a  copious  precipitate: 

Pyrosclerite=(AP03.Cr203),  Si03-f  2(3[MgO.Fe]), . 
SiO3  -f  IJ HO ;  Chonikrite  =  2  APO3,  SiO3 -f  3(3 
[MgO.CaO.FeO],  SiO3)  +  6HO,  are  distinguished 
from  the  other  minerals  of  this  section  by  their 
inferior  hardness=2.5— 3.  The  former  gives 
with  fluxes  the  reactions  of  oxide  of  chromium, 
§§  67  and  68. 

Brc  wsterite  =  (  Sr  O.  Ba  0  ),  Si  O3  +  AP  O8, 3  Si  O3  + 
5HO ;  characterized  by  its  hydrochloric  acid 
solution  giving  a  precipitate  with  sulphuric  acid. 

Stilbite=CaO.Si03+AP03.3Si03-f5HO;Chabazite 
=  3(CaO.NaO),2Si03-f  3(AP03.2Si03)-f-18HO  ; 
Prehnite=2CaO.Si03+AP03.Si03  +  HO.  Fuse 
with  intumescence  to  enamel-like  masses.  Preh- 
nite  yields  but  little  water,  losing  by  ignition 
only  4.3  per  cent. ;  the  others  lose  from  15  to  20 
per  cent. 

I 


130  ELDERHORST'S  MANUAL  OP 

Meerschaum,  see  below ;  Deweylite==2MgO.Si03-j- 

3HO.     Distinguished  by  being  much  less  fusible 

than  the  preceding  (fusibility=5);   the  former 

absorbs  water  with  great  avidity,  the  latter  not. 

Section  2.  Giving  only  traces  or  no  water  in  a  matrass. 

Tachylyte=3(FeO.CaO.NaO),  2Si03-f  APO3,  SiO3. 
Fuses  readily  to  a  black  shining  glass.  Hard- 
ness==6.5 ;  color  black. 

Scapolite=3(Ca0.jSTaO),Si03+3(AP03.Si03).  Col 
or  light.  Hardness=5 — 5.5.  Fuses  with  intu 
mescence  to  a  white,  vesicular  glass. 

W6hlerite=Si03,Nb03,Zr203,CaO,NaO.  Fusibility 
=  3,  forming  a  yellowish  enamel.  The  hydro 
chloric  acid  solution  gives  the  same  reaction  as 
eukolite. 

Labradorite  =  (CaO.NaO),  Si03-f  APOlSiO3 ;  An- 
orthite=3CaO,Si03+3(AP03,Si03).  Fusibility 
=  3 — 4,  without  intumescence,  forming  a  color 
less  glass;  hardness  of  the  former=6,  of  the 
Iatter=6 — T.  Cleavage  perfect. 

Lime  Garnet  (some  varieties)  =  3CaO,  Si03-f  APO3, 
SiO3.  Fusibility=3  ;  not  cleavable. 

Sphene,  some  varieties,  see  below.  Gives  titanium- 
reactions,  §  111. 

Division  5.  Little  affected  by  hydrochloric  acid ;  give  with  fluxes 
the  manganese-reactions. 

Carpholite=Si03,AP03,FeO,MnO,Fe:03,HO.  Oc 
curs  only  in  radiated  and  stellated  tufts.  Color 
straw-yellow ;  silky.  Yields  water. 

Manganese  Garnet=3MnO.Si03-fAP03.Si03.  Col 
or  brownish-red  ;    fus-es  without  intumescence  ; ', 
not  cleavable. 

Epidote  (some  varieties)  =  3CaO,  Si03-f  2([AP03. 
Mn203.Fc203J,SiO'3).  Fusibility=2— 2.5,  intu- 
mesces.  Cleavable.  Color  cherry-red  to  reddish- 
black. 

Rhodonite=3MnO,2Si03.  Fusibility =3,  without 
intumescence.  Color  rose-red  ;  cleavable. 


BLOW-PIPE   ANALYSIS.  131 

Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 

Scheelite=CaO,W03.  Fusibility  =5.  Soluble  in 
hydrochloric  acid,  leaving  a  residue  of  tungstic 
acid,  which  is  soluble  in  ammonia,  and  which 
gives  with  SPh  tho  characteristic  reaction  of 
tungstic  acid ;  see  Table  II. 

Lepidolite=KO,LiO,F,AP03,  SiO3;  Euphyllite= 
SiO3,  APO3,  CaO,  HO ;  Margarite  =  SiO3,  APO3, 
CaO,  HO.  Fusibility  of  lepidolite=2 ;  gives  the 
lithia-reaction,  §  89.  Fusibility  of  euphyllite= 
4.5,  of  margarite=4.  Color  of  euphyllite  white 
to  colorless  j  of  margarite  grayish,  reddish-white, 
yellowish.  All  three  possess  perfect  cleavage. 

Petalite  =  3  (Li  O.  NaO),  2  SiO3  -f  4  (A1203, 3Si  O3)  ; 
Spodumene=  3(LiO.NaO),  2Si03  -f  4(A1203, 
2Si03),  do  not  possess  as  perfect  a  cleavage  as 
the  preceding,  and  greater  hardness ;  hardness 
of  petalite=6 — 6.5,  of spodumene=6.5 — 7.  Both 
give  the  lithia-reaction,  §  89.  Spodumene  fuses 
with  intumescence  to  a  glassy  globule ;  petalite 
fuses  to  a  white  enamel 

Diallage  =  3  (CaO.MgO),  2Si03.  Fusibility  =  3.5 ; 
characterized  by  its  pearly  metallic  lustre;  cleaves 
easily  in  one  direction. 

Harmotonie=BaO,Si03+AP03,2Si03+5HO.  Dis 
tinguished  from  the  other  minerals  of  this  di 
vision  by  yielding  water  in  a  matrass.  Occurs 
usually  in  twin  crystals. 

Axinite=SiOs,Al2O3,CaO,FeO,MnO,B03;  Tounna- 
line=Si03,  APO3,  FeO,  KO,NaO,LiO,B03.  Give 
the  reaction  of  boracic  acid,  §  61.  Axinite  fuses 
readily  with  intumescence  to  a  dark-green  glass. 
Different  varieties  of  tourmaline  show  different 
fusibility.  Hardness  of  axinite=6.5 — ,  of  tour 
maline^ — 7.5. 

Diopside  (white  augite)  =  SCaO,  2S103  -f-  3MgO, 
2Si03 ;  Augite  =  3CaO,  2Si03  -f  3(MgO.  FeO), 


132  ELDERHORST'S  MANUAL  OF 

2S103.  Hardness=6  ;  diopside  fuses  to  a  whitish, 
augite  to  a  black  glass.  Color  of  augite  black 
or  dark-green ;  of  diopside  pale-green  or  gray, 
or  colorless. 

Tremolite  =  CaO.Si03-f  3Mg0.2Si03 ;  Hornblende 
=  CaO.Si03-f  3(MgO.FeO),2Si03.  Hardness= 
5.5  ;  fusibility=3 — 4.  Tremolite  fuses  to  a  white 
or  light-colored  glass,  hornblende  to  a  black  or 
gray  glass  ;  the  former  is  colorless  or  white,  or 
of  light  green,  yellow,  or  gray  color  ;  hornblende 
is  green  or  black. 

Sphene=2(CaO,Si03)-f  CaO,3Ti02.  Fusibility  =3. 
Hardness=5 — 5.5.  Gives  the  titanium-reaction, 
§  111.  Imperfectly  soluble  in  hydrochloric  acid. 

Orthoclase=KO.Si03+AP03,3Si03;  Albite=NaO, 
Si03-f  AF03,3Si03.  Hardness=6.  Fuse  with 
out  intumescence  ;  fusibility  of  orthoclase  =  5,  of 
albite=4  ;  the  latter  colors  the  flame  yellow. 
Not  soluble  in  acids.  With  solution  of  cobalt 
become  blue  on  the  edges,  §  44. 

Zoisite=3CaO.Si03-f2(Al203,Si03);Epidote==CaO, 
Si03-}-2([AP03.Fe203],  SiO3).  Hardness  =  6.5. 
Fusibility  =3 — 3.5;  fuse  with  intumescence, 
zoisite  to  a  white  or  yellowish  slag,  epidote  to  a 
black  or  dark-brown  slag.  Color  of  zoisite  gray, 
yellowish-gray,  grayish-white  ;  of  epidote  green. 

Lime  Garnet=3CaO,Si03+Al203,Si03;  Idocrase= 
3CaO,Si03-f  (Fe203.AP03,Si03 ;  Pyrope=(MgO. 
FeO.  CaO),Si03-f  ( A1203.  Cr203),  SiO3.  Hardness 
=  6.5 — 7.5.  Fusibility  of  lime  garnet  and  idocrasc 
=  3, of  pyrope=4.5.  Idocrase  possesses  cleavage, 
the  others  not.  Pyrope  gives  with  the  fluxes  the 
chromium-reactions. 

(See,  also,  emerald,  euclase,  iolite,  biotite,  and  mus- 
covite.) 

Obsidian,  Pitchstone,  Pearlstone,  and  Pumice= 
SiOs,Al203,NaO,KO,HO,  are  amorphous.  Fusi- 


BLOW-PIPE    ANALYSIS.  133 

bility=  3.5 — 4,fuse  with  intumescence  to  porcelain- 
like  masses,  or  white  vesicular  glasses.  Lustre 
of  obsidian  glassy,  of  pitchstone  greasy,  of  pearl- 
stone  pearly ;  pumice  is  characterized  by  its  po 
rosity. 
CLASS  III.  INFUSIBLE,  OR  FUSIBILITY  ABOVE  5. 

Division  1.  After  ignition  moistened  with  solution  of  cobalt  and 
again  ignited,  assume  a  bright-blue  color. 

With  the  hard,  anhydrous  minerals  of  this  division, 
the  color  is  best  seen  by  reducing  the  substance 
to  a  fine  powder  and  moistening  this  with  the 
solution  of  cobalt.  The  color  appears  only  after 
cooling. 
Section  1.  Giving  much  water  in  a  matrass. 

Alunite=S03,AP03,  KO,  HO  ;  Websterite=Al2O3, 
Si03-f9HO.  Give  a  sulphur-reaction,  §  107. 
Websterite  is  readily  soluble  in  hydrochloric 
acid  ;  alunite  not  visibly  affected. 

(See,  also,  ammonia  alum,  and  potash  alum.) 

Plumbo-Resinite,  see  §  176. 

Calamine,  see  §  214. 

Wavellite  =  4A1203,  3P05  +  18HO  ;  Gibbsite  = 
A1203,P05  +  8HO  ;  Peganite  =  2A1203,P03  +  6 
HO;  Fischerite=2Al2O3,P05+2HO.  Soluble  to 
a  great  extent  in  hydrate  of  potassa.  Give  the 
reactions  of  phosphoric  acid,  §§  94  and  95.  The 
former  two  occur  usually  in  globular  concretions 
of  radiated  structure,  the  latter  two  minutely 
crystalline.  Peganite  loses  on  ignition  24  per 
cent,  of  water,  wavellite  27,  fischerite  29,  gibb- 
site,  35. 

Diaspore  =  APO3,  HO  ;  Clintonite  =  SiO3,  APO3, 
CaO,  MgO,  HO.  Diaspore  is  but  slightly  sol 
uble  in  hydrate  of  potassa ;  clintonite  insoluble ; 
the  former  loses  on  ignition  11|  per  cent,  of 
water,  the  latter  4J.  Hardness  of  diaspore= 
6.5 — 7  ;  of  clintonite=4— 5. 
12 


134  ELDERHORST'S  MANUAL  OF 

Allophane=3  APO3,  2  Si03-fl5HO;  Halloysitc 
=  3  APO3,  4Si03+12HO;  Ochran=AP03,  SiO3 
-f6HO;  Collyrite=3AP03,  Si03-f  15HO.  De 
composed  by  hydrochloric  acid  with  separation 
of  gelatinous  silica.  Hardness  of  allophane=3, 
of  the  others =1 — 2.  Halloysite  loses  on  igni 
tion  16  per  cent,  of  water,  ochran  21,  collyritc  33^. 

Pholerite=Al203,  Si03-f  2HO  ;  Cimolite=AP03, 
3Si03+3HO  ;  Kaolin=3AP03,  4Si03-f  6HO  and 
2AP03,3Si03-f-6HO;  are  all  very  soft  and  earthy, 
and  but  little  affected  by  acids ;  lose  on  ignition 
from  12  to  16  per  cent,  of  water.  Nearly  related 
to  these  minerals  are  the  various  varieties  of 
common  clay,  some  varieties  of  lithomarge  (with 
14  per  cent,  of  water),  and  bole  with  24 — 26  per 
cent,  of  water ;  the  clays  become  plastic  wit  h 
water,  the  latter  two  not. 
Section  2.  Giving  little  or  no  water  in  a  matrass. 

Lazulite=P05,  APO3,  MgO,  FeO,  HO.  Gives  the 
reaction  of  phosphoric  acid,  §  74.  Heated,  loses 
its  blue  color  and  becomes  white.  Not  affected 
by  acids. 

Willemite=3ZnO,  SiO3.  With  solution  of  cobalt 
(§  44)  becomes  blue,  and  green  in  spots.  Gela 
tinizes  with  hydrochloric  acid. 

Myelin=2(Al203,  SiO3)  -f  HO ;  Agalmatolite=Si03, 
APO3,  KO,  HO  ;  Pyrophyllite=3MgO,  2Si03-f 
9  (APO3,  Si03)-f  9HO.  Arc  very  soft,  hardness= 
1 — 2.  Pyrophyllite  is  foliated  like  talc;  before 
the  Blp  swells  up  and  spreads  out  into  fan-like 
shapes,  increasing  to  about  20  times  its  former 
bulk.  The  others  do  not  change  before  the  Blp. 
Myelin  is  partially  decomposed  by  hydrochloric 
acid  ;  agalmatolite  not  affected. 

Muscovite=KO,  Si03-f  4(AP03,  SiO3).  Cleavage 
eminent  in  one  direction ;  folia  elastic.  Does 
not  swell  perceptibly  before  the  Blp,  fusible  in 


BLOW-PIPE    ANALYSIS.  135 

very  thin  laminae.    Not  affected  by  acids.    Hard- 
ness=2.5. 

Disterrite  (variety  of  clintonite),  cleavable  in  one 
direction.  Hardness=4— 5.  Decomposed  by 
concentrated  sulphuric  acid. 

Andalusite=4Al203,3Si03;Kyanite=3Al203,2SiOs; 
are  but  little  affected  by  acids.  Kyanite  occurs 
generally  in  bladed  crystallizations  ;  hardness= 
6 — 7.  Hardness  of  andalusite  =  7.5,  but  variety 
chiastolite  varies  in  hardness  from  3  to  7.5. 

Topaz=2Al2F3+5(Al203,Si03) ;  Lithia  Tourmaline 
=  Si03,  BO3,  AFO3,  MnO,  LiO,  KO.  Not  affected 
by  acids.  Not  completely  soluble  in  SPh,  the 
glass  becomes  opalescent  on  cooling.  Topaz  on 
being  ignited  remains  transparent  and  docs  not 
swell ;  tourmaline  becomes  white  and  swells. 
Topaz  is  cleavable  in  one  direction.  Hardness 
=  8;  tourmaline  is  not  cleavable,  hardness=6.5. 

Corundum  (sapphire)=A!203;  Chrysoberyl=Be(). 
A1203.  Not  affected  by  acids.  When  pulverized, 
slowly  but  completely  soluble  in  SPh  ;  the  glass 
does  not  opalesce  on  cooling.  Hardness  of 
chrysoberyl=8.5,  of  corundum=9  ;  color  of  the 
former  usually  green,  of  the  latter  blue,  red, 
yellow,  brown. 

(Some  varieties  of  Spinel  and  Leucite  assume  a 

blue  color  with  solution  of  cobalt.) 

Division  2.  Moistened  with  solution  of  cobalt  and  ignited,  assume 
a  green  color. 

It  is  sufficient  to  heat  to  redness.  The  minerals  of 
this  division  give  a  coating  of  oxide  of  zinc  on 
charcoal,  §  25. 

Smithsonite,  see  §  213. 

ZincBloorn=(ZnO,C02-fHO)  +  2(ZnO,HO).  Dis 
solves  readily  in  hydrochloric  acid  with  efferves 
cence;  the  solution  gives  with  ammonia  a  white 
precipitate,  soluble  in  an  excess  of  the  reagent. 
Yields  water  in  a  matrass. 


136  ELDERHORST'S  MANUAL  OP 

Willemite  =  3ZnO,Si03;  Calarnine,  see  §  214.  Gela- 
tinize  with  hydrochloric  acid.  Calamine  yields 
water,  willemite  not.  With  solution  of  cobalt 
assume  a  green  color  only  in  spots. 

(See  also  Blende  and  Goslarite.) 

Division  3.  After  ignition  have  an  alkaline  reaction,  and  change 
into  blue  the  color  of  a  moistened  red  litmus- 
paper. 

Brucite=MgO,  HO;  Hydromagnesite=MgO,4HO 
4-  3(MgO,C02).  Yield  much  water  in  a  matrass, 
unlike  the  other  minerals  of  this  division.  Bru- 
cite  dissolves  in  hydrochloric  acid  without  effer 
vescence,  hydromagnesite  with  effervescence;  the 
concentrated  solutions  are  not  precipitated  by 
sulphuric  acid.  Lancasterite  is  a  mixture  of 
brucite  and  hydromagnesite.  Nemalite  is  a 
fibrous  variety  of  brucite,  of  silky  lustre. 

Calcite=CaO.  CO2;  Arragonite=CaO.  CO2.  Dis 
solve  readily  and  with  effervescence  in  dilute 
cold  hydrochloric  acid;  the  concentrated  (but 
not  the  dilute)  solution  gives  a  precipitate  with 
sulphuric  acid.  Arragonite  falls  to  powder 
before  the  Blp,  calcite  not. 

Dolomite  =  MgO.  CO2  +CaO.  CO2;  Magnesite= 
MgO.  CO2.  Do  not,  or  but  slightly,  effervesce 
with  cold  dilute  hydrochloric  acid,  but  dissolve 
readily  on  application  of  heat.  The  concentrated 
solution  of  the  former  gives  a  precipitate  with 
sulphuric  acid,  that  of  the  latter  not. 

A  similar  behavior  shows  the  Breunnerite=(MgO. 
FeO.  MnO),  CO2,  which  on  ignition  becomes 
black  and  slightly  magnetic ;  and  some  varieties 
of  Chalybite,  see  §  163,  and  Diallogite,  see  §  185. 

Strontianite=SrO.C02;Barytocaleite=BaO.C02-f 
CaO.CO2.  Dissolve  with  effervescence  in  dilute 
hydrochloric  acid;  the  solution,  even  if  largely 
diluted  with  water,  gives  a  precipitate  with  sul- 


BLOW-PIPE  ANALYSIS.  137 

phuric  acid.     Strontianite  colors  the  flame  red, 
§  34;  barytocalcite  yellowish-green,  §  35. 

(See  also  Yttrocerite.) 

Division  4.  Completely  soluble,  or  nearly  so,  in  hydrochloric  or 
nitric  acid  without  gelatinizing  or  leaving  a  per 
ceptible  residue  of  silica. 

Chalybite,  see  §  163;  Breunnerite,  see  preceding 
division;  Diallogite,  see  §  185;  Emerald  Nickel, 
see  §  195.  Dissolve  in  heated  hydrochloric  acid 
writh  effervescence. 

Limonite,  see  §  155 ;  Gothite=Fe203,HO.  Become 
black  and  magnetic  in  reduction  flame.  Dissolve  in 
hydrochloric  acid  without  effervescence.  Gb'thite 
occurs  crystallized  and  cleaves  distinctly  in  one 
direction;  loses  10  per  cent,  on  ignition;  limonite 
loses  14^  per  cent. 

(See  also  Hematite  which  in  some  varieties  is 
without  metallic  lustre;  readily  distinguished  by 
red  streak.) 

Blende,  see  §  212;  Marmatite  =  FeS-f-3ZnS;  Green- 
ockite=CdS.  Dissolve  in  hydrochloric  acid  with 
evolution  of  sulphuretted  hydrogen.  Give  the 
sulphur-reaction,  §  107.  Greenockite  gives  on 
charcoal  a  coating  of  oxide  of  cadmium,  §  24,  the 
others  of  oxide  of  zinc,  §  25.  Marmatite  gives 
after  calcination  with  the  fluxes  the  reactions 
of  iron. 

Wad,  see  §  184  ;  Zincite,  see  §  211. 

Earthy  Cobalt,  see  §  133.  Some  varieties  are 
fusible. 

Pitchblende  =  TTO,l?03 ;  Zippeite  =  IPO3  +  xHO. 
Give  with  the  fluxes  the  reactions  of  sesquioxide 
of  uranium  [Table  II].  Give  with  nitric  acid  a 
yellow  solution  in  which  ammonia  produces  a 
sulphur-yellow  precipitate.  Pitchblende  is  black, 
zippeite  yellow. 

Chrome    Ochre=Cr203.      Gives    with   fluxes    the 
12* 


138 


ELDERIIORST'S  MANUAL  OF 


reactions  of  sesquioxidc  of  chromium  [Table  II]. 
Forms  with  hydrate  of  potassa  a  green  solution. 

Turquois  =  P05,Al203,  HO,  CuO.  Color  sky-blue 
and  green.  Gives  the  copper-reaction,  §  74. 
Yields  much  water  in  a  matrass. 

Apatitc=3(3CaO.  PO5)  +  Ca  (01,  F).  Gives  the 
phosphoric  acid  reaction,  §  94.  Fusibility =5. 
Soluble  in  nitric  acid.  Gives  the  fluorine-reac 
tion,  §  76  (always  ?) 

Monazite=P05,CcO,LaO,ThO.  Infusible.  Gives 
the  phosphoric  acid  reaction,  §  94.  Soluble  in 
hydrochloric  acid.  Minute  tabular  crystals  of 
reddish-brown  color. 

Childrenite=  PO5, Al203,FcO,MnO,IIO.  Gives  the 
phosphoric  acid  reaction,  §  94.  With  the  fluxes 
gives  the  reaction  of  iron  and  manganese.  In 
hydrochloric  acid  soluble  with  difficulty.  Yields 
much  water. 

Polycrase=Ti02,Nb03,Zr203,Fe203,Ce-03,U203,  &c. 
Decrepitates,  but  infusible.  Color  black.  On 
fusing  the  pulverized  mineral  with  hydrate  of 
potassa,  boiling  the  fused  mass  with  hydrochloric 
acid,  filtering,  and  boiling  the  filtrate  with  tin 
foil,  the  liquid  assumes  a  blue  color  on  reaching 
a  certain  degree  of  concentration ;  the  color  dis 
appears  on  addition  of  water. 

Fluoceritc=CeF.     Gives  the  reactions  of  fluorine, 
§75,  and   of  sesquioxide   of  cerium,  Table  II. 
Yttroccrite=F,CaO,YO,Ce203,behaves  similarly. 
Division  5.    With  hydrochloric  acid  form  a  jelly,  or  are  decom 
posed  with  separation  of  silica  without  gelatin 
izing. 
Section  1.  Giving  water  in  a  matrass. 

Dioptase  =  3CuO,2Si03  -f  3HO  ;  Chrysocolla,  see 
§  149.  Behave  alike  before  the  Blp ;  the  former 
gelatinizes  with  acids,  the  latter  not. 

Thorite=3ThO,Si03  +  3HO ;  Ccrite=3CeO,Si03  + 


BLOW-PIPE    ANALYSIS.  139 

3HO.  Gelatinize  with  hydrochloric  acid.  Color 
of  thorite  orange-yellow  or  black,  hardness= 
4.5 — 5  j  of  eerite,  brown  to  red  passing  into 
gray,  hardness=5.5. 

Chloropal=Fe203,2Si03-f  3HO.  Color  yellowish- 
green,  amorphous,  of  an  opal-like  appearance. 
Becomes  magnetic  by  ignition ;  gelatinizes.  Small 
pieces  when  thrown  into  a  concentrated  solution 
of  hydrate  of  potassa  lose  the  green  color  and 
become  dark-brown.  Hardness=2 — 3. 

Hisingerite=Fe203,Si03-f  3HO ;  Xylotile=Fe203, 
3Si03+3MgO,2Si03-f  5110.  Become  magnetic 
by  ignition.  Readily  decomposed  by  hydro 
chloric  acid.  Hisingerite  is  black,  imperfectly 
crystallized  and  cleavable  in  one  direction ;  xylo- 
tile  is  light  or  dark  brown,  of  fibrous,  woody 
structure. 

Meerschaum=MgO,Si03-f  2HO.  Gelatinizes  with 
hydrochloric  acid  ;  very  light ;  absorbs  water 
with  great  avidity;  gives  the  magnesia-reaction 
with  solution  of  cobalt,  §  44. 

Schiller-Spar  =  3([MgO.  FeO],  SiO3)  -f  2(MgO,  2 
HO)  ;  Chrysotile  =  3MgO,2Si03  -f  MgO,3HO. 
Possess  a  metallic  pearly  lustre ;  the  former  is 
massive,  cleavable  ;  the  latter  fibrous.  By  igni 
tion  schiller-spar  becomes  brown,  chrysotile 
white.  Both  are  decomposed  by  hydrochloric 
acid,  or  more  readily  by  sulphuric  acid,  without 
gelatinizing. 

Serpentine=2(3MgO,2Si03)x  3(MgO,2HO).  De 
composed  by  concentrated  hydrochloric  acid 
without  gelatinizing.  Usually  massive  and  com 
pact ;  hardness=3 — 4;  loss  by  ignition  12 13 

per  cent.  Of  similar  composition,  and  showing 
a  similar  behavior,  are  the  following  minerals, 
which,  however,  possess  crystalline  structure  and 
cleavage  :  Picrophyll,  hardness=2.5,  loss  by  ig. 


HO  ELDERHORST'S  MANUAL  OP 

nition  10^  per  cent.  ;  Picrosraine,  hardness=2.t, 
loss  by  ignition  9  per  cent. ;  Marmolite,  hardness 
=  2.5 — 3,  loss  by  ignition  15. T  per  cent. ;  Kaem- 
mererite,  hardness=1.5 — 2,  loss  by  ignition  13 
per  cent. 

(See  also  Chlorite  and  Kipidolite  which  are  with  | 
difficulty  decomposed  by  concentrated  hydro 
chloric  acid.) 

Antigorite=3(MgO.FeO),2Si03-f  MgO,HO ;  Mon- 
radite=4(3[MgO.FeO],2Sio3)  + 3HO  ;  Neolite= 
3MgO,2Si03+HO.  Decomposable  by  concen 
trated  hydrochloric  acid  without  gelatinizing. 
Loss  by  ignition  4 — 6  per  cent.  Antigorite  oc 
curs  in  foliated  masses,  hardness=2.5 ;  monra- 
dite,  hardness=6  ;  neolite  in  silky  fibres  or  mas 
sive,  hardness =1. 

(See,  also,  some  varieties  of  Clintonite,  hardness= 

4-5.) 
Section  2.  Giving  only  traces  or  no  water  in  a  matrass. 

Gadolinite  =  SiO3, YO,FeO,CeO,Be203 ;  Gehlenite= 
2(3CaO,Si03)-f2(AP03.Fe203),Si03.  Gelatinize 
with  hydrochloric  acid.  Gadolinite  swells  before 
the  Blp  into  cauliflower-like  masses,  and  some 
times  exhibits  a  vivid  glow  ;  thin  splinters  fusi 
ble  on  the  edges  ;  color  black  to  blackish-green  ; 
hardness=6.5 — 7.  Gehlenite  is  also  fusible  in 
very  thin  splinters;  color  gray  to  grayish-white  ; 
hardness=5.5 — 6. 

Chrysolite  =  3MgO,  SiO3 ;  Chondrodite=2(3MgO, 
SiO3)  -f  MgF.  Gelatinize  with  hydrochloric  acid. 
Color  of  the  former  green,  of  the  latter  mostly 
white,  yellow,  or  brown.  Chondrodite  gives  the 
fluorine-reaction,  §  t6. 

Boltonitc  (a  variety  of  pyroxene)  =  Si03,MgO,FeO, 
APO3.  Cleavage  distinct  in  one  direction.  Color 
yellow.  (See  also  Clintonite.) 

Leucite  =  3KO,  2Si03  -f  3(APO',2Si03).      Decom- 


BLOW-PIPE  ANALYSIS.  141 

posed  by  hydrochloric  acid,  the  silica  separating 
as  a  fine   powder;  some  varieties   become  blue 
with  solution  of  cobalt ;  occurs  usually  in  trape- 
zohedrons.     Color  grayish  or  white. 
Division  6.  Not  belonging  to  either  of  the  preceding  divisions. 

The  remaining  minerals  which  cannot  be  classed 
under  any  of  the  preceding  divisions,  may  be 
divided  according  to  their  hardness  in  two  sec 
tions. 
Section  1.  Hardness  below  Y. 

Biotite  (hexagonal  mica)=(Al203.Fe203),Si03-t-3 
(MgO,KO),Si03 ;  Muscovite  (oblique  mica)= 
KO,Si03-f  4(Al203,Si03)  ;  Talc=6MgO,5Si03+ 
2HO.  Give  little  or  no  water  in  a  matrass  ;  talc 
loses  at  most  5  per  cent.  Cleavage  eminent  in 
one  direction.  Hardness  of  biotite=2.5 — 3,  of 
muscovite=2 — 2.5,  of  talc=l — 1.5.  Biotite  is 
decomposed  by  concentrated  sulphuric  acid,  the 
others  not.  The  laminae  of  biotite  and  musco- 
vite  are  elastic,  of  talc  not.  Soapstone  or  steatite 
is  a  massive,  usually  compact  variety  of  talc  ; 
very  greasy  to  the  feel,  or  like  soap  (see  also 
Pyrophyllite). 

Chlorite  =  2(MgO,Al203)  -f  3(2[MgO.  Fe],  SiO8)  -f 
6HO  ;  Ripidolite  =  (MgO.  FeO),  SiO3  -f  (A1203. 
Fe203),Si03-j-4(MgO,HO.  Loses  by  ignition  12 
per  cent,  of  water.  Cleavage  eminent  in  one 
direction,  laminae  not  elastic  (chlorite  often  mas 
sive  granular).  Hardness  of  chlorite=2 — 2.5,  of 
ripidolite=l — 2.  Decomposed  by  concentrated 
hydrochloric  acid  with  continued  boiling,  more 
readily  by  sulphuric  acid.  Ripidolite  fuses  with 
difficulty  (=5.5)  to  a  grayish-yelk)  w  enamel, 
chlorite  becomes  black  and  slightly  magnetic. 
A  similar  behavior  shows  the  Chloritoid  ;  hard- 
ness=5.5 — 6. 

Bronzite   (hypersthene)  =  3MgO,  2SiO*  -f-  3(CaO- 


142  ELDERIIORST'S  MANUAL  OF 


FcO),  2S103;  Anthophyllite=FeO,Si03+3MgO, 
2S103.  Cleavage  of  bronzite  very  perfect  in  one 
direction;  anthophyllite  cleaves  in  two  directions. 
The  former  is  of  clove-brown  or  pinchbeck-brown 
color,  with  a  pearly-metallic  lustre  ;  the  lustre 
of  anthophyllite  is  much  less  perfect.  Hard- 
ness=5 — 5.5. 

Wolframites* WO3,  is  soluble  in  hydrate  of  potassa; 
the  solution  gives  with  nitric  acid  a  yellow  pre 
cipitate  which  on  boiling  becomes  lemon-yellow. 
Occurs  in  soft,  earthy,  yellow  masses. 

Scheelite=CaO,W03.  Fusibility=5  ;  hardness  = 
4.5 — 5.  The  pulverized  mineral,  on  being  boiled 
with  nitric  acid,  leaves  a  lemon-yellow  residue 
of  tungstic  acid.  Gives  the  reactions  of  tungstic 
acid  [Table  II]. 

Cassiterite,  see  §  209. 

Anatase,  Rutile,  and  Brookite=Ti02.  Give  the 
reactions  of  titanic  acid  [Table  II].  On  fusing 
th<3  pulverized  minerals  with  hydrate  of  potassa, 
dissolving  the  fused  mass  in  hydrochloric  acid 
and  boiling  the  solution  with  metallic  tin,  it  as 
sumes  a  violet  color,  which  turns  to  red  on  addi 
tion  of  water.  Color  of  anatase,  various  shades 
of  brown  passing  into  indigo-blue ;  of  rutile 
mostly  brownish-red  or  red,  sometimes  yellowish 
or  black ;  of  brookite,  hair-brown,  yellowish  or 
reddish  (variety  arkansitc  is  iron-black).  Hard 
ness  of  anatase=5.5 — G;  of  rutile=G — 6,5;  of 
brookite =5.5— 6, 

Acschynite  and  Pyrochlore=Nb03,Ti02,Zr703,Ce'' 
03,CaO,  &c.  Treated  like  the  preceding  with 
potassa,  &c.,  the  solution  on  reaching  a  certain 
degree  of  concentration  assumes  a  fine  blue  color, 
which,  on  addition  of  water,  docs  not  change  to 
red,  but  gradually  disappears.  Acschynite  swells 


BLOW-PIPE    ANALYSIS.  143 

before  the  Blp  and  turns  yellow ;  pyrochlore  does 
not  swell  and  becomes  grayish. 

Opal=Si03-f  xHO.  Before  the  Blp  yields  water 
and  becomes  opaque ;  fuses  with  carbonate  of 
soda  to  a  clear  bead,  with  effervescence.  Infusi 
ble.  Boiled  \vith  hydrate  of  potassa,  it  dissolves 
completely  or  to  a  great  extent;  the  solution 
gives  a  gelatinous  precipitate  with  chloride  of 
ammonium.  Hardness— 6 — 6.5. 

Xenotime=3YO,P05.  Color,  various  shades  of 
brown  or  flesh-red.  Hardness=4 — 5.  Gives  the 
phosphoric  acid  reaction,  §  94.  Infusible.  With 
salt  of  phosphorus  dissolves  with  great  difficulty 
to  a  colorless  glass. 

[See  also  Childrenite  and  Orthoclase.] 
Section  2.  Hardness=7,  or  above. 

[See  Cassiterite,  Rutile,  and  Opal  of  the  preceding 
section  whose  hardness  sometimes  approaches  7.] 

Quartz— SiO3.  The  various  varieties  of  quartz,  as 
rock-crystal,  amethyst,  hornstone,  flint,  chalce 
dony,  &c.,  are  infusible  and  unalterable  before 
the  Blp,  and  fuse  with  carbonate  of  soda  to  a 
transparent  bead,  with  effervescence.  Hard 
ness^. 

Iolite  =  2  (3[MgO.FeO],  2Si03)  +  5(A1203,  SiO3)  ; 
Staurotide=2(Al203.Fe203),  SiO3.  Hardness= 
7 — T.5.  Do  not  fuse  to  a  transparent  glass  with 
carbonate  of  soda.  Fusibility  of  iolite=5 — 5.5  ; 
color  blue,  grayish.  Staurotide  is  infusible ; 
color  brownish-red,  brown ;  crystals  often  cruci 
form. 

Beryl  =  3BeO,  2Si03+  A1203,  2Si03;  Euclase  =  2 
(3BeO,  Si03)  +  2Al203,  SiO3;  Phenacite=3BeO, 
Si03;Zircon=Zr03,Si03.  Hardness=7.5.  Beryl 
and  euclase  turn  milk-white  with  strong  heat 
and  become  rounded  on  the  edges;  beryl  crystal 
lizes  in  hexagonal  prisms,  and  possesses  pretty 


244  ELDERIIORST'S  MANUAL  OP 

distinct  basal  cleavage,  color  usually  pale-green 
or  emerald-green;  euclase  crystallizes  in  clino- 
rhombic  prisms  and  possesses  distinct  cleavage 
in  two  directions  at  right  angles  to  each  other ; 
color  pale  mountain-green  passing  into  blue  and 
white.  Phenacite  and  zircon  do  no  change  be 
fore  the  blow-pipe,  excepting  that  zircon  becomes 
colorless ;  color  red,  yellow,  or  colorless,  zircon 
sometimes  brown  or  gray;  phcnacitc  is  a  little 
harder  (=8)  than  zircon. 

Ouvarovite  (lime-chrome-garnet)  =  SCaO,  SiO3  -f 
Cr203,Si03.  Infusible.  Hardness  =  7.5  _  8. 
Gives  with  fluxes  the  chromium  reactions 
[Table  II]. 

Spinel  =  MgO,  A1203  ;  Pleonastc  =  (MgO.  FeO), 
A1203;  Gahnite=(ZnO.MgO),Si03.  Hardness= 
7.5 — 8.  Occur  almost  exclusively  in  octahedral 
crystals.  Spinel  and  pleonaste,  when  pulverized, 
are  soluble  in  salt  of  phosphorus;  color  of  spinel 
red,  blue,  brownish ;  of  pleonaste  black.  Gahiiite 
Js  almost  insoluble  in  salt  of  phosphorus  and 
borax;  color  dark-green  or  black.  Kreittonite 
is  a  black  spinel  containing  zinc  and  iron, 
slightly  magnetic  before  ignition. 

Diamond=  C.  Characterized  by  its  hardness,  which 
surpasses  that  of  corundum. 


TABLES. 


(145) 


146 


ELDERHORST  S    MANUAL    OF 


TABLE  L— BEHAVIOE  OF  THE  ALKALINE 

BEFORE  THE 


On  Ch  alone,  and  in  the 
forceps. 

With  Carbonate  of  Soda 
on  Ch. 

1.  BARYTA. 
BaO. 

The  Hydrate  fuses,  boils, 
intumesces,  and  is  finally 
absorbed  by  the  Ch.  The 
Carbonate  fuses  readily  to 
a  transparent  glass,  which, 
on  cooling,  becomes  enamel- 
white.  In  the  forceps  it 
colors  the  outer  flame  yel 
lowish-green. 

Fuses  Avith  Sd  to  a  homo 
geneous  mass,  which  is  ab 
sorbed  by  the  Ch. 

2.  STRONTIA. 
SrO. 

The  Hydrate  behaves  like 
hydrate  of  Baryta.  The 
Carbonate  fuses  only  at 
the  edges,  and  swells  out 
in  arborescent  ramifications 
which  emit  a  brilliant  light, 
and,  when  heated  with  the 
RF1,  impart  to  it  a  reddish 
tinge  ;  shows  after  cooling 
alkaline  reaction.  In  the 
forceps,  colors  the  outer 
flame  purple. 

Caustic  Strontiais  insolu 
ble.  The  Carbonate,  mixed 
with  its  own  volume  of  Sd, 
fuses  into  a  limpid  glass, 
which  becomes  enamel-white 
on  cooling.  At  a  greater 
heat  the  mass  enters  into 
ebullition,  and  caustic  Strori- 
tia  is  formed,  which  is  ab 
sorbed  by  the  Ch. 

3.  LIME. 
CaO. 

Caustic  Lime  suffers  no 
alteration.  The  Carbonate 
loses  carbonic  acid,  becomes 
whiter  and  more  luminous, 
and  shows  after  cooling  al 
kaline  reaction.  In  the  for 
ceps  it  colors  the  outer  flame 
pale-red. 

Insoluble.  The  Sd  passes 
into  the  Ch,  and  leaves  the 
Lime  unaltered  on  its  sur 
face. 

4.  MAGNESIA. 

MgO. 

Undergoes  no  alterations. 
The  Carbonate  becomes 
caustic  and  luminous. 

It  behaves  like  Lime. 

5.  ALUMINA. 

A1203. 

Not  changed. 

Forms  an  infusible  com 
pound,  Avith  slight  intumes 
cence.  The  excess  of  Sd  is 
absorbed  by  the  Ch. 

BLOW-PIPE    ANALYSIS. 


147 


EARTHS  AND  THE  EARTHS  PROPER 
BLOW-PIPE. 


With  Bx  on  Platinum  Wire. 


With  SPk  on  Platinum  Wire. 


The  Carbonate  dissolves  with  ef 
fervescence  to  a  limpid  glass  which, 
when  in  a  certain  state  of  saturation, 
may  be  made  opaque  by  flaming; 
when  still  more  saturated,  it  be 
comes  opaque  on  cooling,  even  with 
out  flaming. 


As  with  Borax. 


Presents  the  same  phenomena  as 
Barvta. 


Presents  the  same  phenomena  as 
Baryta. 


Readily  dissolved  to  a  limpid  glass, 
which  becomes  opaque  by  flaming. 
The  Carbonate  dissolves  with  effer 
vescence.  On  a  large  addition  of 
Lime  the  glass  crystallizes  on  cooling, 
but  does  not  become  enamel-white. 


Soluble  in  large  quantities  to  a 
limpid  glass  which,  when  sufficient 
Lime  is  present,  becomes  opaque 
by  flaming.  When  saturated,  the 
glass  becomes  enamel-white  on  cool 
ing. 


It  behaves  like  Lime,  but  does  not 
crystallize  so  well. 


Readily  soluble  to  a  limpid  glass, 
which  becomes  opaque  by  flaming. 
When  saturated,  it  becomes,  on  cool 
ing,  enamel-white. 


Dissolves  slowly  to  a  limpid  glass, 
which  remains  so  on  cooling,  and 
which  cannot  be  made  cloudy  by 
flaming.  A  large  quantity  of  Alu 
mina  makes  the  glass  cloudy;  on 
cooling,  it  then  assumes  a  crystalline 
surface. 


Soluble  to  a  limpid  glass,  which 
remains  clear  under  all  circum 
stances.  If  too  much  Alumina  is 
added,  the  undissolved  portion  be 
comes  translucent. 


H8 


ELDERIIORST  S    MANUAL    OP 


TABLE  L  — CON- 


On  Ch  alone,  and  in  the 
forceps. 

With  Carbonate  of  Soda 
on  Ch. 

6.  GLUCINA. 
BeO. 

Not  changed. 

Insoluble. 

7.  YTTRIA. 
YO. 

Not  changed. 

Insoluble. 

8.    ZlRCONIA. 
Zr«0». 

Infusible,  but  emitting  a 
very  glaring  light. 

Insoluble. 

BLOW  PIPE    ANALYSIS. 


149 


TINTJED. 


With  Ex  on  Platinum  Wire. 

With  SPh  on  Platinum  Wire. 

Soluble  in  large  quantities  to  a 
limpid  glass,  which  becomes  opaque 
by  naming.  When  Glucina  is  pre 
sent  in  excess,  it  becomes  enamel- 
white  on  cooling. 

As  with  Borax. 

Like  Glucina. 

Like  Glucina. 

Like  Glucina. 

Dissolves  more  slowly  than 
Borax. 

with 

13 


150 


ELDERHORST  S    MANUAL    OF 


TABLE  II.  — BEHAVIOR  OF  THE  METAL- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

1.  ANTIMONIOUS 
ACID. 

SbO3. 

OF1:  It  is  displaced  with 
out  change,  and  deposited 
upon  another  part  of  the 
Ch. 
HF1:  It  is  reduced  and 
volatilized.     A  Ct  of  an- 
timonious  acid  is  deposit 
ed  on  the  Ch,  and  a  green 
ish-blue  color  imparted  to 
the  flame. 

On  Ch  very  readily  re 
duced  in  OF1  and  RF1. 
The  metal  fumes  and 
coats  the  Ch  with  anti- 
monious  acid. 

2.  ARSENOUS 
ACID. 
AsO3. 

Volatile  below  red  heat. 

On  Ch  reduced,  with 
emission  of  arsenical 
fumes,  which  are  charac 
terized  by  a  strong  garlic 
odor. 

3.  TEROXIDE  OF 
BISMUTH. 
BIO3. 

OF1:    On  platinum  foil 
it  fuses  readily  to  a  dark- 
brown    mass,    which,    on 
cooling,  becomes  pale  yel 
low. 
On  Ch  in  OF1  and  RF1 
reduced   to    metallic    bis 
muth,    which,    with   long 
blowing,  vaporizes,  coating 
the  Ch  with  yellow  oxide. 
The  Ct,  when  touched  with 
the  RF1,  disappears  with 
out  coloring  the  flame. 

Easily  reduced  to  me 
tallic  bismuth. 

4.  OXIDE  OF 
CADMIUM. 
CdO. 

OF1  :    On   platinum  foil 
unchanged. 
11F1:    On    Ch  it   disap 
pears  in  a  short  time,  and 
deposits   all  over  the  Ch 
a  dark-yellow  or  reddish- 
brown  powder  ;    the  color 
can   only  be  clearly  dis 
cerned  after  cooling. 

OF1:  Insoluble. 
RF1:  On  Ch  readily  re 
duced  ;  the  metal  vapor 
izes  and  deposits  a  dark- 
yellow  or  reddish-brown 
Ct  on  the  Ch. 

BLOW-PIPE    ANALYSIS. 


151 


LIC  OXIDES  BEFOEE  THE  BLOW-PIPE. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1 :  Dissolves  in  large  quantities 
to  a  limpid  glass,  which,  while  hot, 
appears  yellowish,  but  after  cooling, 
colorless. 

RF1 :  The  glass,  when  treated  only 
for  a  short  time  in  the  OF1,  becomes 
on  Ch  grayish  and  cloudy  from  par 
ticles  of  reduced  antimony.  With 
tin  it  becomes  gray  or  black. 


OH :  Dissolves  with  effervescence 
to  a  limpid  glass,  which,  while  hot, 
is  slightly  yellowish. 

RF1:  On  Ch  the  saturated  bead 
becomes  at  first  cloudy,  but  after 
wards  clear  again,  owing  to  the  vola 
tilization  of  the  reduced  antimony. 
Treated  with  tin,  the  glass  becomes, 
after  cooling,  gray,  even  if  but  very 
little  antimonious  acid  is  present. 
With  strong  blowing  it  becomes  clear 
again.  


OF1:  A  small  quantity  is  easily 
dissolved  to  a  clear  yellow  glass, 
which,  on  cooling,  becomes  colorless. 
On  a  large  addition  of  oxide,  the 
glass,  while  hot,  is  yellowish-red, 
becomes  yellow  on  cooling,  and  when 
cold  is  opalescent. 

RF1:  On  Ch  the  glass  becomes  at 
first  gray  and  cloudy,  the  oxide  is 
reduced  to  metal  with  effervescence, 
and  the  bead  becomes  clear  again. 
An  addition  of  tin  accelerates  the 
process. 


OF1 :  Readily  dissolved  to  a  lim 
pid  yellow  glass,  which,  on  cooling, 
becomes  colorless.  When  a  greater 
quantity  of  oxide  is  present,  the 
glass  may  be  made  enamel-white  by 
naming,  and  on  a  still  larger  addi 
tion  it  becomes  by  itself  enamel- 
white  on  cooling. 

RF1 :  On  Ch,  particularly  when 
tin  is  added,  the  glass  remains 
colorless  and  limpid  while  hot,  but 
becomes,  on  cooling,  dark-gray  and 
opaque. 


OF1 :  Soluble  in  large  quantity  to 
a  limpid  yellowish  glass,  becoming 
almost  colorless  on  cooling.  When 
highly  saturated,  it  may  be  made 
enamel-white  by  flaming,  and  when 
still  more  oxide  is  present,  it  be 
comes  by  itself  enamel-white  on 
cooling. 

RF1 :  Placed  on  Ch,  it  enters  into 
ebullition  ;  the  oxide  is  reduced ;  the 
reduced  metal  vaporizes  immediate 
ly  and  deposits  a  dark-yellow  Ct. 


OF1 :  Soluble  in  large  quantity  to 
a  limpid  glass  which,  while  hot,  is 
yellowish,  but  colorless  when  cold  ; 
when  saturated,  it  becomes  enamel- 
white  on  cooling. 

RF1:  On  Ch  the  oxide  becomes 
slowly  and  imperfectly  reduced.  The 
reduced  metal  deposits  a  very  feeble 
Ct  of  dark-yellow  color.  The  color 
is  only  clearly  seen  when  the  mass 
is  cold.  An  addition  of  tin  facili 
tates  the  reduction. 


152 


ELDERHORST  S    MANUAL    OF 

TABLE  II.  —  CON 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

5.  SESQUIOXIDE 
OF  CERIUM.- 

Ce203. 

Not  changed. 

Insoluble.  The  Sd  passes 
into  the  Ch  ;   the  sesqui- 
oxide  is  reduced  to  prot 
oxide,  which   remains  on 
the   Ch   as    a    light-gray 
powder. 

6.  SESQUIOXIDE 
OF  CHROMIUM. 
Cr'O3. 

Not  changed. 

OF1  :   On  platinum  wire 
soluble  to  a  dark  yellow 
ish-brown  glass,  which  on 
cooling   becomes    opaque 
and  yellow. 
11F1  :  The  glass  becomes 
opaque  and  green  on  cool 
ing.     On  Ch  it  cannot  be 
reduced  to  metal  ;  the  Sd 
passes  into  the  Ch,  and  the 
oxide  remains  behind  as  a 
green  powder. 

7.  OXIDE  OF 
COBALT. 
CoO. 

OF1:  Not  changed. 
RF1:    It  is  reduced   to 
metal,  but  does  not  fuse: 
the  mass  is  attracted  by 
the  magnet,  and  assumes 
metallic    lustre    by    fric 
tion. 

OF1:  On  platinum  wire 
a  very  small   quantity  is 
dissolved  to  a  transparent 
mass    of    a    pale-reddish 
color,  which    on    cooling 
becomes  gray. 
RF1  :  On  Ch  reduced  to 
a  gray  magnetic  powder. 

8.  OXIDE  OF 
COPPER. 
CuO. 

OF1  :  Fuses  to  a  black 
globule,    which   becomes 
reduced  when  it  is  in  con 
tact  with  the  Ch. 
RF1:  Reduced  to  metal 
at  a   temperature   below 
the  melting-point  of  cop 
per.     When   the   heat  is 
increased  a  globule  of  me 
tallic  copper  is  obtained. 

OF1  :  On  platinum  wire 
soluble  to  a  limpid  glass 
of  green   color  ;    on    cool 
ing  it  becomes  opaque  and 
white. 
KF1  :  On  Ch  easily  re 
duced   to    metal,    which, 
when  the  temperature  is 
sufficiently  high,  fuses  to 
one  or  more  globules. 

BLOW-PIPE    ANALYSIS. 


153 


TINUED. 


With  Ex  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1:  Soluble  to  a  limpid  glass  of 
dark-yellow  or  red  color,  which 
changes  on  cooling  to  yellow.  When 
highly  saturated  with  oxide  the  glass 
becomes  on  cooling  enamel-white. 

RF1 :  The  yellow  glass  becomes 
colorless.  A  highly  saturated  bead 
becomes  on  cooling  enamel-white 
and  crystalline. 


OF1 :  As  with  Bx,  but  on  cooling 
colorless. 

RF1:  Perfectly  colorless,  hot  and 
cold.  Becomes  never  opaque  on 
cooling,  however  large  the  amount 
of  oxide. 


OF1:  Dissolves  but  slowly,  but 
colors  intensively.  If  little  of  the 
oxide  is  present,  the  glass,  while  hot, 
is  yellow;  when  cold,  yellowish- 
green  ;  with  more  oxide  it  is  dark- 
red  while  hot,  becomes  yellow  on 
cooling,  and  when  perfectly  cold  has 
a  fine  yellowish-green  color. 

RF1:  The  glass  is  green,  hot  and 
cold.  The  intensity  of  the  color  de 
pends  on  the  amount  of  oxide  pre 
sent.  Tin  causes  no  change. 


OF1 :  Soluble  to  a  limpid  glasn, 
which,  while  hot,  appears  reddish ; 
when  cold  it  has  a  tine  green  color., 

RF1:  As  in  OF1. 


OF1 :  Colors  very  intensively.  The 
glass  appears  pure  smalt-blue,  hot 
and  cold.  An  excess  of  oxide  im 
parts  to  the  bead  a  deep  bluish-black 
color. 

RF1:  As  inOFl. 


OF1 :  As  with  Bx,  but  for  the  same 
quantity  of  oxide  the  color  is  not 
quite  so  deep. 

RF1:   AsinOFl. 


OF1 :  A  small  addition  of  oxide 
makes  the  glass  appear  green  while 
hot,  but  blue  when  cold.  A  large 
quantity  imparts  to  it  a  very  deep- 
green  color  while  hot,  becoming 
greenish-blue  when  cold. 

RF1 :  A  glass  containing  a  certain 
quantity  of  oxide  becomes  colorless, 
but  on  cooling  becomes  opaque  and 
red  (suboxide).  On  Ch  the  copper 
may  be  precipitated  in  the  metallic 
state,  the  bead  becoming  in  conse 
quence  colorless.  A  glass  contain 
ing  protoxide,  when  treated  on  Ch 
with  tin,  becomes  on  cooling  brown- 
iah-red  and  opaque. 


OF1:    As  with   Bx,   but  for  the 

same  amount  of  oxide  the  coloration 
is  not  so  deep. 

RF1 :  A  glass  containing  a  large 
quantity  of  oxide  becomes  dark- 
green,  which  in  the  moment  of  re 
frigeration  changes  suddenly  to 
brownish-red  and  opaque.  A  glass 
containing  but  little  oxide,  when 
treated  on  Ch  with  tin,  appears  color 
less  while  hot,  but  becomes  brown 
ish-red  and  opaque  on  cooling.  . 


154 


ELDERHORST  S    MANUAL  OP 


TABLE  II.  _  CON- 


Metallic  Oxides  in 
Alphabetical  Order. 


On  Charcoal  alone. 


With  Carbonate  of  Soda. 


9.  TEROXIDE  OF 
GOLD. 
AuO3. 


When  heated  to  igni 
tion  it  becomes  reduced 
to  metal  in  OF1  and  KF1. 
The  metal  fuses  easily  to 
a  globule. 


Does  not  dissolve  in  the 
Sd,  but  is  easily  reduced, 
in  both  flames.  The  metal 
fuses  readily  to  a  globule. 
The  Sd  passes  into  the  Ch. 


10.  SESQUIOXIDE 
OF  IRON. 

Fe203. 


OF1 :  Not  changed. 
RF1 :     Becomes    black 
and  magnetic. 


OF1:   Insoluble. 

HF1:  On  Ch  it  is  re 
duced  ;  the  mass,  when 
placed  in  a  mortar,  pul 
verized,  and  repeatedly 
washed  with  water  to  re 
move  the  adherent  Ch 
particles,  yields  a  gray 
metallic  powder  which  is 
attracted  by  the  magnet. 


11. 


BlNOXIDE  OF 

IRIDIUM. 
IrO2. 


At  a  red  heat  becomes 
reduced ;  the  reduced 
metal  is  infusible. 


OF1 :  Does  not  dissolve 
in  the  Sd,  but  becomes 
reduced ;  the  metal  can 
not  be  fused  to  a  globule. 

RF1:  AsinOFl. 


12.  OXIDE  OF 

LEAD. 

PbO. 


Minium,  when  heated  on 
platinum  foil,  blackens ; 
on  increasing  the  tem 
perature  it  changes  into 
yellow  oxide,  which  final 
ly  fuses  to  a  yellow  glass. 
On  Ch  in  OF1  and  RF1 
almost  instantaneously 
reduced  to  metal  which, 
with  continued  blowing, 
vaporizes,  and  covers  the 
Ch  with  yellow  oxide, 
surrounded  by  a  faint 
white  ring  of  carbonate. 
The  Ct,  when  touched 
with  the  RF1,  disappears, 
imparting  to  the  flame  an 
azure-blue  tinge. 


OFl:  On  platinum  wire 
readily  dissolved  to  a  lim 
pid  glass  which,  on  cool 
ing,  becomes  yellowish 
and  opaque. 

11F1:  On  Ch  reduced  to 
metal  which,  with  con 
tinued  blowing,  covers 
the  Ch  with  oxide. 


BLOW-PIPE    AN7ALYSI8. 


155 


TINTJED. 


With  Bx  on  Platinum  Wire. 

With  SPh  on  Platinum  Wire. 

As  with  Carbonate  of  Soda. 

As  with  Carbonate  of  Soda. 

OF1:  A   small    amount   of  oxide 
causes  the  glass  to  look  yellow  while 
hot,    colorless    when    cold.     When 
more  of  the   oxide  is   present  the 
glass,  while  hot,  appears   red,  and 
yellow   when   cold.     A  still   larger 
quantity  makes  the   glass  dark-red 
while   hot,   and   dark-yellow  when 
cold. 
RF1:    The  glass-  becomes  bottle- 
green.     Treated  on  Ch  with  tin    it 
becomes,  at  first,   bottle-green,  but 
afterwards  pure  vitriol-green. 

OF1  :  When  at  a  certain  point  of 
saturation  the  glass,  whi'le  hot,  ap 
pears  yellowish-red,  and  becomes  on 
cooling  at  first  yellow,  then  green 
ish,  and  finally  colorless.    On  a  very 
large  addition  of  oxide  it  appears, 
while    hot,  deep-red,   becoming,  on 
cooling,  brownish-red,  then  of  a  dirty- 
green  color,  and  finally  brownish-red, 
RF1  :  A  glass  containing  but  little 
of  the  oxide  suffers  no  visible  change. 
When  more  of  the  oxide  is  present  it 
is  red  while  hot,  and  on  cooling  be 
comes  at  first  yellow,  then  greenish, 
and  finally  reddish.     Treated  with 
tin  on  Ch  the  glass  on  cooling  be 
comes    at  first  green,    and    finally 
colorless. 

As  with  Carbonate  of  Soda. 

As  with  Carbonate  of  Soda. 

OF1:   Easily  soluble  to  a  limpid 
yellow  glass  which  on   cooling  be 
comes  colorless.     If  much  oxide  is 
present  it  may  be  made  cloudy  by 
flaming.     A  still  larger  addition  of 
oxide  causes  the   bead  to   become 
enamel-yellow  on  cooling. 
RF1  :  The  glass  diffuses  itself  over 
the  Ch  and  becomes  cloudy.     With 
continued  blowing  the  oxide  is  re 
duced  to  metal,  with  effervescence, 
and  the  glass  becomes  clear  again. 

OF1  :  As  with  Bx.     But  to  obtain 
a  glass  which  appears  yellow  while 
hot,  a  large  addition  of  the  oxide  is 
required. 
RFl:    On   Ch   the  glass  becomes 
grayish  and  cloudy.    This  phenome 
non  is  better  observed  when  tin  is 
added  ;  but  the  glass  can  never  be 
made  quite  opaque.     If  much  of  the 
oxide  is  present,  the   Ch  becomes 
coated. 

156 


ELDERHORST  S    MANUAL    OF 

TABLE  II.  — CON- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

13.  SESQUIOXIDE 
OF  MANGANESE. 
Mn203. 

OF1  :  Insoluble.  When 
the  temperature   is  suffi 
ciently    high,    both    the 
sesquioxide  and  the  per 
oxide  are  converted  into 
a  reddish-brown  powder 
(MnO+Mn'O3). 
RF1  :  The  same  effect. 

OF1  :  On  platinum  wire  . 
or     foil     a     very     small 
quantity   dissolves   to    a 
transparent  green   mass, 
which  on  cooling  becomes 
opaque  and  bluish-green. 
RF1:  On  Chit  cannot  be 
reduced  to  metal  ;  the  Sd 
passes   into  the   Ch   and 
leaves  the   protoxide  be 
hind. 

14.  PROTOXIDE 
OF  MERCURY. 
HgO. 

Instantly  reduced  and 
volatilized. 

Heated    in    a   matrass 
to  redness,  it  is  reduced 
and  vaporized.     The  va 
pors  condense  in  the  neck 
of  the  matrass  and  form 
a  metallic  coating. 

15.  MOLYBDIC 
ACID. 
MoO3. 

OF1  :    Fuses,    becomes 
brown,  vaporizes,  and  de 
posits  on  the  Ch  a  yellow 
Ct,  which  nearest  to  the 
assay  is  crystalline.     On 
cooling   the    Ct   becomes 
white,   and   the    crystals 
colorless. 
RF1:  The  greater  part 
of  the  assay  is  absorbed 
by  the   Ch,  and   may  be 
reduced  to  metal  at  a  suf 
ficiently    high    tempera 
ture  ;  the  metal  is  in  the 
shape  of  a  gray  powder. 

OF1  :  On  platinum  wire 
dissolves    with    efferves 
cence  to  a  limpid  glass, 
which  on  cooling  becomes 
milk-white. 
RF1  :  Fuses  with  effer 
vescence.  The  fused  mass 
is   absorbed  by  the   Ch, 
and  part  of  the  acid   is 
reduced   to   metal  which 
may   be    obtained    as    a 
steel-gray  powder. 

16.  OXIDE  OF 
NICKEL. 
NiO. 

OF1:  Not  changed. 
RF1  :  On  Ch  reduced  to 
metal  ;  the  spongy  mass 
cannot  be  fused  to  a  glo 
bule,  but  assumes  metal 
lic  lustre  by  friction  ;  it  is 
attracted  by  the  magnet. 

OF1:  Insoluble. 
RF1:    Easily    reduced 
to   metal,   in    the    shape 
of   bright,  white  scales, 
which   are    attracted   by 
the  magnet. 

BLOW-PIPE    ANALYSIS. 


157 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1 :  Colors  very  intensively. — 
The  glass,  while  hot,  is  violet,  on 
cooling  it  assumes  a  reddish  tinge. 
When  much  manganese  is  added, 
the  glass  becomes  quite  black  and 
opaque ;  but  the  color  can  be  seen 
when  the  glass,  while  soft,  is  flat 
tened  with  the  forceps. 

RF1 :  The  glass  becomes  colorless. 
If  the  color  was  very  dark,  the 
phenomenon  is  best  observed  on  Ch 
with  addition  of  tin. 


OF1:  A  considerable  addition  of 
manganese  must  be  made  to  produce 
a  colored  glass;  it  then  appears, 
while  hot,  brownish-violet,  and 
reddish-violet  when  cold,  but  never 
opaque.  If  the  glass  contains  so 
small  a  quantity  of  manganese  that 
it  appears  colorless,  an  addition  of 
nitre  will  produce  the  characteristic 
coloration. 

RF1:  Becomes  very  soon  color 
less. 


OF1 :  Dissolved  in  large  quantities 
to  a  limpid  glass  which,  while  hot, 
appears  yellow,  but  colorless  on 
cooling.  A  very  large  amount  of 
acid  causes  the  glass  to  appear  dark- 
yellow  while  hot,  and  opaline  when 
cold. 

RF1:  A  highly  saturated  bead 
becomes  brown,  and  opaque  when 
still  more  acid  is  present. 


OF1:  Easily  soluble  to  a  limpid 
glass ;  if  but  little  of  the  acid  is 
present  it  is  yellowish-green  while 
hot,  but  when  cold  almost  colorless. 
On  Ch  the  glass  becomes  very  dark, 
and  on  cooling  assumes  a  beautiful 
green  color. 

RF1:  The  glass, assumes  a  very 
dark,  dirty-green  color  which,  on 
cooling,  becomes  beautiful  bright- 
green.  The  same  on  Ch  ;  tin  deepens 
the  color  a  little. 


OF1 :  A  small  quantity  colors  the 
bead  violet  while  hot ;  when  cold, 
pale  reddish-brown.  More  oxide 
makes  the  coloration  deeper. 

RF1 :  The  glass  becomes  gray  and 
cloudy,  or  even  opaque.  With  con 
tinued  blowing  the  minute  particles 
of  reduced  metal  collect  together 
and  the  glass  becomes  colorless. 
This  takes  more  readily  place  on 
Ch,  especially  when  tin  is  added. 
The  nickel  then  unites  with  the  tin 
to  a  globule. 
14 


OF1:  Soluble  to  a  reddish  glass 
which,  on  cooling,  becomes  yellow. 
A  larger  addition  causes  the  glass 
to  appear  brownish-red  while  hot, 
and  reddish-yellow  when  cold. 

RF1:  On  platinum  wire  not 
changed.  On  Ch  with  tin  it  becomes, 
at  first,  gray  and  opaque;  with 
continued  blowing  the  nickel  be 
comes  reduced,  and  the  glass  clear 
again  and  colorless. 


158 


ELDERHORST  8    MANUAL  OF 


TABLE  II.  — CON- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

17.    BlNOXIDE  OF 

OSMIUM. 
OsO2. 

OF1  :    Converted    into 
osmic  acid  which,  with 
out  depositing  a  Ct,  vol 
atilizes  with  its  peculiar 
pungent  odor. 
11F1  :  Easily  reduced  to 
a    dark-brown     and    in 
fusible  metallic  powder. 

Easily  reduced  to  an 
infusible  metallic  pow 
der. 

18.    PROTOXIDE 
OF  PALLADIUM. 
PdO. 

Reduced  at  a  red-heat  ; 
but  the  metallic  particles 
are  infusible. 

Insoluble.  The  Sd 
passes  into  the  Ch,  and 
leaves  the  Palladium  be 
hind. 

19.    BlNOXIDE    OF 

PLATINUM. 
PtOa. 

Like  Palladium. 

Like  Palladium. 

20.    PROTOXIDE 
OF  SILVER. 
AgO. 

Easily  reduced  to  me 
tallic  silver,  which  unites 
to  one  or  more  globules. 

Instantly  reduced.  The 
Sd  passes  into  the  Ch, 
and  the  metal  unites  to 
one  or  more  globules. 

31.  TELLUROUS 
ACID. 
TeO*. 

OF1  :  Fuses,  and  is  re 
duced  with  effervescence. 
The    reduced   metal   be 
comes    instantly    vapor 
ized  and  covers  the  Ch 
with  tellurous  acid;  the 
Ct  usually  has  a  red  or 
dark-yellow  edge. 
RF1:  As  in  OF1  ;  the 
outer  flame  appears  of  a 
bluish-green  color. 

Soluble,  on   platinum- 
wire,    to    a   limpid    and 
colorless  glass,  which  on 
cooling  becomes  white. 
On    Ch    reduced    and 
volatilized,   depositing  a 
Ct  of  tellurous  acid. 

22.    BlNOXIDE    OF 

TIN. 
SnO2. 

OF1  :     The     protoxide 
burns,  like  tinder,  to  bin- 
oxide.     The  binoxide  be 
comes  very  luminous  and 
appears,  while  hot,  yel 
lowish,  but  assumes    on 
cooling     a      dirty-white 
color. 
RF1  :  With  a  powerful 
and   continued   flame   it 
maybe  reduced  to  metal. 

OF1  :  On  platinum-wire  ( 
it   forms  with    Sd,   with 
effervescence,   an   infusi 
ble  compound. 
RF1:    On    Ch   reduced 
to  metallic  tin. 

BLOW-PIPE  ANALYSIS. 


159 


TINUED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1  and  RF1 :  Reduced,  but  not 
dissolved;  the  metallic  particles 
cannot  be  fused  to  a  globule. 


As  with  Bx. 


Like  Palladium. 


Like  Palladium. 


OF1:  In  part  dissolved,  and  in 
part  reduced.  On  cooling,  the  glass 
becomes  opalescent  or  milk-white, 
according  to  the  amount  of  oxide 
present. 

RF1 :  The  glass  at  first  becomes 
gray,  but  afterwards  limpid  and 
colorless. 


OF1 :  Imparts  to  the  bead  a  yel 
lowish  color.  When  much  of  the 
oxide  is  present,  the  glass,  when 
cold,  is  opalescent,  and  appears  yel 
lowish  at  daylight,  reddish  at  can 
dle-light. 

RF1 :  As  with  Bx. 


OF1:  Soluble  to  a  limpid  and 
colorless  glass  which,  on  Ch,  be 
comes  gray  from  reduced  metal. 

RF1 :  On  Ch  becomes  at  first  gray, 
afterwards  colorless.  The  Ch  be 
comes  coated  with  tellurous  acid. 


As  with  Borax. 


OF1:  A  very  small  quantity  dis 
solves  slowly  to  a  limpid  and  color 
less  glass,  which  remains  so  on 
cooling. 

RF1:  From  a  highly  saturated 
glass  a  part  of  the  oxide  may  be 
reduced  on  Ch. 


,  OF1 :  As  with  Borax. 

RF1:  The  glass,  containing  oxide, 
suffers  no  change. 


160 


ELDERHORST  S    MANUAL    OP 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical  Order, 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

23.  TITANIC 
ACID. 
TiO2. 

0  F  1  :      Assumes,     on 
heating,   a  yellow  color, 
and  becomes  white  again 
on   cooling.      Suffers    no 
other  change. 
RF1:  AsinOFl. 

OF1  :  on  Ch  it  dissolves, 
with     effervescence,      to 
a      dark  -yellow      glass, 
which,   on  cooling,  crys 
tallizes.     When  cold  it  is 
grayish-white. 
RF1:   As  inOFl;  can 
not  be  reduced  to  metal. 

24.  TUNGSTIC 
ACID. 
WO3. 

OF1:  Not  changed;  at 
a  very  high  temperature 
converted  into  oxide. 
RF1:    Blackens,  being 
converted  into  oxide,  but 
does  not  fuse. 

OF1:  On  platinum  wire 
it  dissolves   to   a   limpid 
and    deep  -yellow   glass, 
which,    on    cooling,    be 
comes     crystalline      and 
opaque,  and  of  white  or 
yellowish  color. 
RF1:    With  very  little 
Sd  on  Ch  it  is  reduced  to 
metal;    with  more  Sd  it 
forms  a  yellow  compound 
of  metallic  lustre,  which 
passes  into  the  Ch. 

25.  SESQUIOXIDE 
OF  URANIUM. 
U203. 

OF1:      Infusible;    but 
assumes  a  dirty  yellow 
ish-green  color. 
HF1  :   Blackens,  owing 
to  the  formation  of  prot 
oxide. 

OF1  :  Insoluble.     With 
a  certain  amount  of  Sd 
the    mass   becomes    yel 
lowish-brown,    and   with 
more  passes  into  the  Ch. 
RF1:    As   in    OF1;    no 
reduction  to  metal  takes 
place. 

26.  YANADIC 
ACID. 
VO3. 

Fusible.  Where  it  is 
in  contact  with  the  Ch 
it  becomes  reduced  and 
passes  into  the  Ch.  The 
rest  assumes  the  lustre 
and  color  of  graphite. 

Unites     to     a    fusible 
mass  which  is   absorbed 
by  the  Ch. 

BLOW-PIPE  ANALYSIS. 


161 


TITHED. 


With  Bx  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1:  Easily  soluble  to  a  limpid 
glass  which,  when  containing  a  large 
quantity,  appears  yellow  while  hot, 
but  becomes  colorless  on  cooling. 
When  containing  a  very  large  quan 
tity  it  is  enamel-white  when  cold.  . 

RF1:  W°en  containing  but  little 
titanic  acid  the  glass  becomes  yel 
low  ;  -when  more,  dark-yellow  to 
brown.  A  saturated  glass  becomes 
enamel-blue  by  flaming. 


OF1 :  Easily  dissolved  to  a  limpid 
glass  which,  when  containing  a  large 
quantity,  appears  yellow  while  hot, 
but  becomes  colorless  on  cooling. 

RF1 :  Appears  yellow  wliile  hot, 
but,  on  cooling,  reddens  and  finally 
assumes  a  violet  color.  If  iron  is 
present  the  glass,  on  cooling,  be 
comes  brownish-red ;  with  tin  on 
Ch  the  glass  becomes  violet,  unless 
the  amount  of  iron  be  very  consid 
erable. 


OF1 :  Like  titanic  acid. 

RF1 :  A  glass,  containing  but  little 
tungstic  acid,  is  not  changed.  When 
more,  it  becomes  yellow  and,  on  cool 
ing,  yellowish-brown.  On  Ch  the 
same  reaction  is  produced  with  a 
less  saturated  bead.  Tin  deepens 
the  colors. 


OF1 :  Easily  dissolved  to  a  limpid 
and  colorless  bead,  which  when 
highly  saturated,  appears  yellow 
while  hot. 

RF1 :  With  little  blowing  the  glass 
appears,  while  hot,  of  a  dirty  green 
color,  blue  on  cooling;  with  strong 
blowing  it  becomes,  on  cooling,  blu 
ish-green.  On  Ch  with  tin,  deep 
green.  If  iron  is  present  the  glass, 
on  cooling,  becomes  brownish-red ; 
with  tin  on  Ch  the  glass  becomes 
blue  or,  .if  the  amount  of  iron  is 
considerable,  green. 


OF1 :  Behaves  like  sesquioxide  of 
iron.  When  highly  saturated  the 
glass  may  be  made  enamel-yellow 
by  flaming. 

RF1 :  Behaves  like  sesquioxide  of 
iron.  The  green  bead,  when  at  a 
certain  point  of  saturation,  may  be 
made  black  by  flaming.  On  Ch  with 
tin  it  becomes  dark-yellow. 


OF1 :  Dissolves  to  a  limpid  yellow 
glass  which,  on  cooling,  becomes 
yellowish-green . 

IIF1:  The  glass  assumes  a  dirty 
green  color  which,  on  cooling, 
changes  to  a  fine  green.  With  tin 
on  Ch  the  color  deepens. 


OF1 :  Dissolved  to  a  limpid  glass 
which,  when  the  quantity  of  vanadic 
acid  is  small,  appears  colorless,  when 
larger  yellow,  and  which,  on  cooling, 
becomes  oreenish. 

RF1 :  The  glass,  while  hot,  appears 
brownish,  and  assumes  a  fine  green 
color  on  cooling. 
14* 


OF1  :  Soluble  to  a  limpid  glass 
which,  if  sufficient  vanadic  acid  is 
present,  appears  dark-yellow  while 
hot,  and  becomes  light-yellow  on 
cooling. 

RF1 :  As  with  Borax. 


lea 


ELDERHORST'S  MANUAL  OF 


TABLE  II.— CON- 


Metallic  Oxides  in 
Alphabetical  Order. 

On  Charcoal  alone. 

With  Carbonate  of  Soda. 

OF1  :  When  heated  be 

comes  yellow  and,  on  cool 

OF1:  Insoluble. 

ing,  white  again.    It  fuses 

RF1:  On  Ch  it  becomes 

27.  OXIDE  OF 
ZINC. 

not,  but  becomes  very  lu 
minous. 
RF1:  Is  slowly  reduced; 

reduced.      The  metal  va 
porizes  and  coats  the  Ch 
with  oxide.    With  a  pow 

ZnO. 

the     reduced    metal    be 

erful  flame  the  character 

comes  rapidly  re-oxidized 

istic  zinc-flame  is  gome- 

and  the  oxide  deposited 

times  produced. 

on  another  place  of  the 

Ch. 

BLOW-PIPE   ANALYSIS. 


163 


TINUED. 


With  Ex  on  Platinum  Wire. 


With  SPh  on  Platinum  Wire. 


OF1:  Dissolves  readily,  and  in 
large  quantity,  to  a  limpid  glass, 
which  appears  yellowish  while  hot ; 
on  cooling  it  is  colorless.  When 
much  of  the  oxide  is  present,  the 
glass  may  be  made  enamel-white 
by  flaming;  and  on  a  still  larger 
addition  it  becomes  enamel-white  on 
cooling. 

RF1 :  The  saturated  glass  becomes 
at  first  gray  and  cloudy,  and  finally 
transparent  again.  On  Ch  the  oxide 
becomes  reduced,  the  metal  vaporizes 
and  coats  the  Ch  with  oxide. 


As  with  Borax. 


164 


ELDERHORST  S    MANUAL    OP 


TABLE  III— THE  METALLIC  OXIDES  ARRANGED 

THEY  IMPART 

WITH  BORAX  IN  OXYDATION  FLAME  PRODUCE  : 


HOT 
AND    1 
COLD. 


r. —  Colorless  Beads. 

Silica,  Alumina,  Binoxide  of  Tin,  "1 
Baryta,    Strontia,    Lime,   Magnesia,  ' 
Glucina,    Yttria,    Zirconia,    Thoria, 
Oxide  of  Lanthanium,  Oxide  of  Sil 
ver,  Tantalic  Acid,  Niobic  Acid,  Tel- 
lurous  Acid. 

Titanic  Acid,  Tungstic  Acid,Molyb- 
dic  Acid,  Oxides  of  Zinc,  Cadmium, 
Lead,  Bismuth,  and  Antimony. 


b. —  Yellow  Beads. 

Titanic  Acid,  Tungstic  Acid,  Ox 
ides  of  Zinc,  and  Cadmium. 


HOT.   < 


when  highly  saturated 
opaque  (white)  by  flam 
ing. 


when  feebly  saturated. 


Oxides    of    Lead,    Bismuth,    and 
Antimony. 

Sesquioxides  of  Cerium,  Iron,  and 
Uranium. 

Sesquioxide  of  Chromium,  when  fully  saturated  ;  when  cold, 
yellowish-green. 

Vanadic  Acid  ;  when  cold,  pale-green. 


when   highly  saturated; 
on  cooling  colorless,  and 
cloudy  by  flaming, 
when    highly  saturated ; 
on  cooling  colorless. 
when   feebly   saturated  ; 
on  cooling  colorless. 


c. — Bed  to  Brown  Beads. 

f       Sesquioxide  of  Cerium  ;    on   cooling  yellow,  enamel-like  by 
f   flaming. 

j        Sesquioxide  of  Iron  ;  on  cooling,  yellow. 

TT         j       Sesquioxide  of  Uranium  ;  on  cooling  yellow,  enamel-yellow  by 
1    flaming. 

Sesquioxide  of  Chromium;  on  cooling  yellowish-green. 

Sesquioxide  of  Iron,  containing  Manganese ;  on  cooling  yel- 
(  lowish-red. 

{Oxide  of  Nickel  (reddish-brown  to  brown);  violet  while  hot. 
Sesquioxide  of  Manganese  (violet-red);  violet  while  hot. 
Oxide  of  Nickel,  containing  Cobalt;  violet  while  hot. 

d. —  Violet  Beads  (amethyst-colored). 

{Oxide  of  Nickel :  on  cooling,  reddish-brown  to  brown. 
Sesquioxide  of  Manganese  ;  on  cooling,  violet-red. 
Oxide  of  Nickel,  containing  Cobalt ;  on  cooling,  brownish. 


BLOW-PIPE    ANALYSIS.  165 

WITH  REFERENCE  TO  THE  COLORS  WHICH 
TO  THE  FLUXES. 


HOT 

AND 

COLD. 


HOT.  { 


WITH  BORAX  IN  REDUCTION  FLAME  PRODUCE  : 

a. —  Colorless  Beads. 

Silica,  Alumina,  Binoxide  of  Tin. 

Baryta,  Strontia,  Lime,  Magnesia,     "j 

Glucina,  Yttria,  Zirconia,  Thoria,  Ox-  |   when  highly  saturated 
ides  of  Lanthanium  and  Cerium,  Tan-   f  cloudy  by  flaming, 
talic  Acid.  J 

Sesquioxide  of  Manganese;  sometimes,  on  cooling,  pale  rose- 
colored. 

Niobie  Acid ;  when  feebly  saturated. 

Oxides    of  Silver,  Zinc,  Cadmium,  "j  with    strong    blowing  ; 
Lead,  Bismuth,  Antimony,  Nickel,  Tel-  \  with     feeble     blowing 
.  lurous  Acid.  J  gray. 

Oxide  of  Copper  ;  when   highly    saturated  on  cooling  opaque 

d  red. 


b. —  Yellow  to  Brown  Beads. 

Titanic  Acid  (yellow  to  brown);  when  highly  saturated  onarnel- 
blue  by  flaming. 

HOT.  \       Tungstic  Acid  (yellow  to  dark-yellow) ;  when  cold  brownish. 
Molybdic  Acid  (brown  to  opaque). 
Yanadic  Acid  (brownish)  ;  green  when  cold. 


c. — Blue  Beads. 
HOT.  {      Oxide  of  Cobalt ;  retains  its  color  on  cooling. 


d. — Green  Beads. 
HOT    f      Sesquioxide  of  Iron  (yellowish-green)  ;  especially  when  cold. 

Sesquioxide  of  Uranium  (yellowish-green)  ;  when  highly  satu- 
p  j  rated  black  by  flaming. 

I/OLD.  |^      Sesquioxide  of  Chromium  (light  to  dark  emerald-green). 

HOT.  \      Yanadic  Acid ;  brownish  while  hot. 


166  ELDERHORST'S  MANUAL  or 

TABLE  III.— CON- 

WITH  BORAX  IN  OXYDATION  FLAME  PRODUCE: 

e. — Blue  Beads. 

HOT.    \      Oxide  of  Cobalt ;  retains  its  color  on  cooling. 
COLD    I      Oxide  of  Copper  (when  highly  saturated  greenish-blue) ;  green 

1  -while  hot.  I 


f— Green  Beads. 

Oxide  of  Copper  ;  when  cold  blue  or  greenish-blue. 

N   on  cooling  the    color 
changes,  according  to 


HOT.   - 


Sesquioxide  of  Iron,  containing  Co 
balt  or  copper. 

Oxide  of  Copper,  containing  Iron  or 
Nickel. 


the  proportion  in 
which  the  various  ox 
ides  are  present,  to 
light-green,  blue,  or 


yellow. 

f      Sesquioxide  of  Chromium,   yellowish-green  ;   yellovr  to   red 
COLD.  \  while  hot. 

(     Vanadic  Acid,  greenish  ;  yellow  while  hot. 


BLOW-PIPE    ANALYSIS.  l$f 

TINUED. 

WITH  BORAX  IN  REDUCTION  FLAME  PRODUCE: 

e. — Gray  and  Cloudy  Beads. 

[  Oxides  of  Silver,  Zinc,  Cadmium,]  with  feeble  blowing; 
Lead,  Bismuth,  Antimony,  Nickel,  J-  with  strong  blowing 
Tellurous  Acid.  J  colorless. 

(^     Niobic  Acid ;  when  highly  saturated. 


COLD.  I  £ 


/. — Red  and  Opaque  Beads. 
COLD.  {      Oxide  of  Copper,  when  highly  saturated;  colorless  while   hot 


168 


ELDERIIORST  S    MANUAL    OF 


TABLE   III.— CON- 


WITH   SALT   OF   PHOSPHORUS  IN    OXYDATION    FLAME   PRODUCE: 
a. —  Colorless  Beads. 

Silicic  Acid;  soluble  only  in  minute  quantity. 
Alumina,  Binoxide  of  .Tin  ;  soluble  with  difficulty. 
Baryta,    Strontia,    Lime,  Magnesia,  ]  when   highly  saturated 
Glucina,  Yttria,  Zirconia,  Thoria,  Ox-  >•  become       opaque       by 
ide  of  Lanthanium,  Tellurous  Acid.       j  flaming. 

too  highly  satu- 


HOT 

AND 

COLD. 


HOT.  , 


Acids  of  Tantalium,  Niobium,  Titan 
ium,  Tungsten,  Antimony;  Oxides  of 
Zinc,  Cadmium,  Lead,  Bismuth. 

b. —  Yellow  Beads. 

m    Acids  of  Tantalium,  Niobium,  Titan- 1     h       h;  } }     8aturated 
mm,  Tungsten,  Antimony;  Oxides  of  L0iorlcssSonycoolin(r. 
Zinc,  Cadmium,  Lead,  Bismuth.  J 

Oxide  of  Silver,  yellowish  ;  when  cold  opalescent. 
Sesquioxide  of  Iron.  1  when    feebly  saturated  ; 

"  "  Cerium.  J  on  cooling  colorless. 

"  "   Uranium  ;  when  cold  yellowish-green. 

Vanadic  Acid,  deep-yellow;  when  cold  of  a  lighter  shade. 

COLD.  -J  Oxide  of  Nickel ;  while  hot  reddish. 

c. — Red  Beads. 
f      Sesquioxide  of  Iron.  1  when  highly  saturated; 

"  "  Cerium.  j  when  cold  yellow. 

Oxide  of  Nickel,  reddish;  when  cold  yellow. 
Sesquioxide  of  Chromium,  reddish  ;  when  cold  emerald-green. 

d. —  Violet  Beads. 

•      Sesquioxide  of  Manganese,  brownish-violet;  on   cooling   pale 
reddish-violet. 
Oxide  of  Didymium  ;  when  cold  of  a  lighter  shade. 

e. — Blue  Beads. 

Oxide  of  Cobalt;  when  cold  of  the  same  color. 
Oxide  of  Copper ;  green  while  hot. 
/. — Green  Beads. 

^  on     cooling    the    color 

Sesquioxide  of  Iron,  containing  Co-  j  changes,    according    to 
bait  or  Copper.  {  the  proportion  in  which 

Oxide  of  Copper,  containing  Iron  or  j  the  various  oxides   are 
NickeL  j  present,  to  light-green, 

j  blue,  or  yellow. 


HOT. 


HOT. 


HOT.   \ 
COLD.  \ 


HOT. 


~ 

COLD. 


Oxide  of  Copper;  when  cold  blue  or  greenish  blue. 
Molybdic  Acid,  yellowish-green  ;  when  cold  of  a  lighter  shade. 
Sesquioxide  of  Uranium,  yellowish-green  ;  while  hot  yellow. 
Sesquioxide  of  Chromium,  emerald-green  •  while  hot  reddish. 


BLOW-PIPE    ANALYSIS. 


169 


TINUED. 


HOT 

AND 

COLD. 


TT 


COLD  X 
' 


COLD, 


WITH  SALT  OF  PHOSPHORUS  IN  REDUCTION  FLAME  PRODUCE  : 
a. — Colorless  Beads. 

Silica,  but  slightly  soluble. 

Alumina,  Binoxide  of  Tin,  soluble  with  difficulty. 

Baryta,  Strontia,  Lime,  jMajjnesia,  )     ,       i_«  1.1  ,LJI_ 

Glucina,  Yttria,  Zirconia,  ThorTa,  Ox'  [  when  hlghl? grated  be- 
ide  of  Lanthanium.  J  come  °Pa(*lie  b?  flaming. 

Oxides  of  Didymium,  Cerium,  Manganese. 

Oxides  of  Silver,  Zinc,  Cadmium, 
Lead,  Bismuth. 

Tantalic  Acid,  Antimonious  Acid, 
Tellurous  Acid. 

Oxide  of  Nickel,  on  Ch. 


with  continued  blowing. 


b.— Yellow  to  Red  Beads. 

Sesquioxide  of  Iron;  on  cooling  greenish,  then  reddisji. 
Titanic  Acid,  yellow  ;  on  cooling  violet. 
Vanadic  Acid,  brownish  ;  when  cold  emerald-green. 
Titanic  Acid  containing  Iron.  )  yellow ;        when        cold 

Tungstic  "  "  "  j  blood-red. 


Niobic       " 
c.  —  Violet  Beads. 


)  brownish-red  ;  when  cold 
}  deep-yellow. 


COLD.  { 
15 


Niobic  Acid,  when  highly  saturated  ;  while  hot  of  a  pale  dirtv- 
blue  color. 

Titanic  Acid;  yellow  while  hot. 

d.  —  Blue  Beads. 

Oxide  of  Cobalt  ;  of  the  same  color  when  hot. 
Tungstic  Acid  ;  while  hot  brownish. 

Niobic  Acid,  when  very  highly  saturated  ;  while  hot  of  a  dirty- 
blue  color. 

e.  —  Green  Beads. 

Sesquioxide  of  Uranium  ;  while  hot  less  bright. 
Molybdic  Acid  ;  while  hot  of  a  dirty-green  color. 
Vanadic  Acid  ;  while  hot  brownish  * 
Sesquioxide  of  Chromium  ;  while  hot  reddish. 

f.  —  Gray  and  Cloudy  Beads. 

Oxides  of  Silver,  Zinc,  Cadmium,)  takes  quickest  place  on 
Lead,  Bismuth,  Antimony,  Nickel  ;  I  Ch;  with  continued  blow- 
Tellurous  Acid.  j  ing  colorless. 

g.  —  Red  and  Opaque  Beads. 

Oxide  of  Copper,  when  highly  saturated,  or  with  Tin  on  Ch 


INDEX. 


ACICULAR  BISMUTH,  116. 

Acids,  volatile,  tests  for,  26. 

Acmite,  124. 

Actinolite,  110. 

Aeschynite,  142. 

Agalniatolite,  134. 

Aikinite,  116. 

Albite,  132. 

Allanite,  117,  123. 

Allophane,  134. 

Allochroite,  124. 

Almandine,  110,  124. 

Altaite,  114. 

Alumina,  tests  for,  31,  146. 

Alunite,  133. 

Amalgam,  86,  117. 

Amalgams,  test  for,  27,  29. 

Amblygonite,  127. 

Ammonia,  test  for,  27,  40. 

"          salts  of,  test  for,  27. 
Ammonia-alum,  126. 
Analcime,  129. 
Anatase,  142. 
Andalusite,  135. 
Anglarite,  123. 
Anglesite,  82,  120. 
Anhydrite,  126. 
Annabergite,  89,  122. 
Anthophyllite,  142. 
Anthracite,  95. 
Antigorite,  140. 
Antimonial  copper,  115. 

silver,  89. 
Antmionious  acid,  tests  for,  27, 

150. 
Antimony,  metallic,  tests  for,  29, 

30,  34. 


Antimony,  test  for,  when  in  com 
bination,  40. 
ores  of,  63. 
"          sulphides  of,  test  for, 

28. 

sulphides  of,  test  for, 
when  in  combina 
tion,  40. 

oxide  of,  test,  27. 
Apatite,  127,  138. 
Apophyllite,  129. 
Apparatus,  list  of,  21,  24. 
Arseoxene,  119. 
Arfvedsonite,  124. 
Argentiferous  sulphide  of  cop 
per,  92. 

Arkansite,  118. 
Arragonite,  136. 
Arsenates,  test  for,  34. 
Arsenic,  metallic,  tests  for,  27, 

29,  30,  34. 
ores  of,  64. 
"          sulphides  of,  test  for, 

28. 

test  for,  when  in  com 
bination,  41. 
test  for,  in  arsenates 

and  arsenites,  41. 
Arsenical  pyrites,  78,  113. 

copper,  71. 
Arseniosiderite,  122. 
Arsenolite,  65,  119. 
Arsenous  acid,  tests  for,  27,  41, 

150. 

Asphaltum,  96. 
Atakamite,  72,  121. 
Augite,  131. 

(171) 


112 


INDEX. 


Axinite,  131. 
Azurite,  73,  121. 

BARIUM,  salts  of,  test  for,  33. 

Baryta,  tests  for,  146. 

Barytes,  126. 

Barytocalcite,  136. 

Berthierite,  64,  115. 

Beryl,  143. 

Berzelianite,  113, 

Beudantite,  122. 

Biotite,  141. 

Bituminous  coal,  95. 

Bismuth,  metallic,tests  for,29,30. 

"          oxide   of,   change   by 

heat,  29. 
"     tests  for,  150. 
test  for,  when  in  com 
bination,  43. 

"          ores  of,  65. 
Bismuth  ochre,  67. 
Bismuthine,  66,  116. 
Bismutite,  66,  125. 
Black  manganese,  85. 
Blende,  93,  118,  136,  137. 
Blow-pipe  lamp,  21. 
Blue  malachite,  73. 
Bog  manganese,  85. 
Boltonite,  140. 
Bone-ash,  24. 

Boracic  acid,  as  reagent,  22. 
tests  for,  34,  43. 
Boracite,  127. 
Borax,  125. 

"       as  reagent,  23. 
Botryogen,  122. 
Boulangerite,  81,  114. 
Bournonite,  80,  114. 
Braunite,  85,  117. 
Breithauptite,  115. 
Breunnerite,  136,  137. 
Brewsterite,  129. 
Brittle  silver  ore,  91. 
Brochantite,  121. 
Bromine,  test  for,  44. 


Bromic  silver,  90. 
Bromyrite,  90. 
Bronzite,  141. 
Brookite,  142. 
Brown  coal,  96. 
Brown  hematite,  76. 
Brucite,  136. 

CACOXENE,  123. 

Cadmium,  metallic,  test  for,  30. 
test  for  small  quanti 
ties  of,  44. 

"         alloys  of,  test  for,  27. 

"         oxide  of,  tests  for,  150. 
Calamine,  94,  133,  136. 
Calcination  of  assays,  34. 
Calcite,  136. 

Calcium,  salts  of,  test  for,  33. 
Calomel,  86,  119. 
Capillary  pyrites,  88. 
Carbonic  acid,  test  for,  26. 
Carpholite,  130. 
Cassiterite,  92,  142. 
Celestine,  126. 
Cerasine,  81,  120. 
Cerite,  138. 

Cerium,  oxide  of,  tests  for,  152. 
Cerusite,  81,  120. 
Chabazite,  129. 
Chalcolite,  121. 
Chalcophyllite,  121. 
Chalcopyrite,  69. 
Chalybite,  78,  137. 
Childrenite,  138,  143. 
Chiolite,  126. 
Chloantite,  113. 
Chlorine,  test  for,  44. 
Chlorite,  140,  141. 
Chloropal,  139. 
Chloro-bromide  of  silver,  90. 
Chondrodite,  140. 
Chonikritc,  129. 
Chrome  ochre,  137. 
Chromic  iron,  67,  118. 
Chromium,  ores  of,  67.  •« 


INDEX. 


173 


Chromium,  oxide  of,  tests  for, 

45,  152. 

Chrysoberyl,  135. 
Chrysoeolla,  74,  133. 
Chrysolite,  140. 
Chrysotile,  139. 
Cryolite,  126. 
Cimolite,  134. 
Cinnabar,  87,  115,  119. 
"        test  for,  28. 
Clausthalite,  113. 
Clintonite,  133,  140. 
Cobalt,  test  for,  in  arsenides,  45. 
"  "       in  sulphides,  45. 

"  "       when  in  combi 

nation     with 
metals,  45. 
"       nitrateof,  as  reagent,  122. 

oxide  of,  tests  for,  152. 
"       ores  of,  67. 
Cobalt  bloom,  68. 
Cobalt  pyrites,  68. 
Cobaltine,  68,  113. 
Collyrite,  134. 
Columbite,  118. 
Common  coal,  95. 
Common  salt,  125. 
Copiapite,  122. 

Copper,  test  for,  in  sulphides,  47. 
"  "      when  in  combi 

nation  with 
other  metals, 
46,  47. 

"  "     when  in  combi 

nation    with 
tin,  60. 
ores  of,  69. 

"       oxide  of,  tests  for,  152. 
"  "      as  reagent,  22. 

"       salts  of,  tests  for,  33,  47. 
Copper  glance,  70,  116. 
"       nickel,  87,  113. 
"       pyrites,  69,  116. 
"       vitriol,  73. 
Copperas,  79. 
15* 


Coquimbite,  122. 
Corneous  lead,  81. 
Corundum,  135. 
Covelline,  121. 
Crocidolite,  124. 
Crocoisite,  83,  119. 
Cronstedtite,  123. 
Cryolite,  126. 
Cuban,  116. 

Cupellation,  process  of,  58. 
Cuproplumbite,  116. 
Cyanogen,  test  for,  27. 
Cyanosite,  74,  121. 

DATHOLITE,  127. 
Dark-red  silver  ore,  91. 
Deweylite,  130. 
Diallage,  131. 
Diallogite,  85,  136. 
Diamond,  144. 
Diaspore,  133. 
Dioptase,  138. 
Diopside,  131. 
Discrasite,  89,  115. 
Disterrite,  135. 
Dolomite,  136. 
Domeykite,  71,  133. 
Dufrenite,  123. 
Dufrenoysite,  81,  113. 

EARTHY  COBALT,  69,  137. 

Ehlite,  121. 

Electrum,  113. 

Embolite,  89. 

Emerald  nickel,  88,  137. 

Epidote,  130. 

Epsomite,  125. 

Erinite,  121. 

Erubescite,  70. 

Erythrine,  68,  122. 

Eucairite,  114. 

Euchroite,  121. 

Euclase,  143. 

Eudialite,  128. 

Eukolite,  128. 


174 


INDEX. 


Eulytine,  124. 

Euphyllite,  131. 

Examination  in  a  closed  glass 

tube,  26. 
"  in  an  open  glass 

tube,  28. 
"  on  charcoal,  29. 

in  the  forceps,  32. 
"  with   borax   and 

salt    of    phos 
phorus,  34. 
"  with  carbonate  of 

soda,  35. 

"  with  solution  of 

cobalt,  37. 

FISCHERITE,  133. 
Flaming,  process  of,  35. 
Fluocerite,  138. 
Fluor,  126. 

Fluor  spar,  as  reagent,  23. 
Fluorine,  tests  for,  48. 
Fossil  fuel,  95. 
Franklinite,  86,  118. 
Fusibility,  scale  of,  109. 

GADOLINITE,  140. 
Gahnite,  144. 
Galena,  80,  115. 
Gay-Lussite,  126. 
Gehlenite,  140. 
Geocronite,  81,  115. 
Gersdorffite,  88,  113. 
Gibbsite,  133. 
Glaserite,  125. 
Glauberite,  126. 
Glauber  salt,  125. 
Glucina,  tests  for,  148. 
Gold,  test  for,  when  in  combi 
nation,  49. 

"      ores  of,  74. 

"      oxide  of,  tests  for,  154. 
Goslarite,  126,  136. 
Gcethite,  137. 
Graphic  tellurium,  75. 


Graphite,  118. 

Gray  antimony,  63,  109. 

"     copper,  70. 

"     ore  of  manganese,  84. 
Green  earth,  124. 

"      vitriol,  79,  122. 
Greenockite,  137. 
Grunauite,  116. 
Gypsum,  126. 

HALLOYSITE,  134. 
Hardness,  scale  of,  62. 
Harmotome,  131. 
Hauerite,  115,  127. 
Hausmannite,  85,  117. 
Hauyne,  128. 
Hedenbergite,  124. 
Hedyphane,  119. 
Kelvin,  127. 

Hematite,  76,  117, 118,  123,  137. 
Heteromorphite,  81. 
Hessite,  114. 
Hisingcrite,  124,  139. 
Horn  quicksilver,  86. 
Horn  silver,  89,  119. 
Hornblende,  124,  132. 
Hureaulite,  122. 
Hydroboracite,  126. 
Hydromagnesite,  136. 
Hypersthene,  141. 

IDOCRASE,  132. 

Ilmenite,  78. 
lodic  silver,  90. 
Iodine,  test  for,  50. 
lodyrite,  90,  119. 
lolitc,  143. 
Iridium,  ores  of,  75. 

"        oxide  of,  tests  for,  154. 
Iridosmine,  75,  118. 
Iron,  metallic,  as  reagent,  24. 
"     test  for,  when  in  combina 
tion,  50,  51. 

"  "         in  sulphides  and 

arsenides,  50. 


INDEX. 


Iron,  oxide  of,  tests  for,  1 54. 

"  "      change  by  heat, 

29. 

"     ores  of,  76. 
Iron  garnet,  110,  124. 
Iron  pyrites,  79,  116. 

JAMESONITE,  81,  114. 

KAOLIN,  134. 

Kerargyrite,  89. 
Kermesite,  64. 
Kilbrikenite,  115. 
Kreittonite,  144. 
Kyanite,  135. 

LABRADORITE,  130. 

Lanarkite,  120. 

Lapis  lazuli,  128. 

Laumontite,  128. 

Lavendulan,  69. 

Lazulite,  134. 

Lead,  metallic,  as  reagent,  24. 

"          "         tests  for,  30,  34. 

"     test  for,  when  in  combina 
tion,  50,  51. 

"      oxide  of,  change  bv  heat, 

30. 
"        tests  for,  154. 

"     ores  of,  79. 

"     phosphate  of,  test  for,  51. 
Leadhillite,  82,  120. 
Lead  vitriol,  82. 
Lepidolite,  124,  131. 
Leucite,  135,  140. 
Libethenite,  121,  122. 
Lievrite,  117,  123. 
Light-red  silver  ore,  91. 
Lime,  tests  for,  146. 
Lime-garnet,  130,  132. 
Lime-chrome-garnet,  144. 
Lime-iron-garnet,  124. 
Limonite,  76,  118,  124,  137. 
Linnaeite,  68,  116. 
Linarite,  120. 


Liroconite,  121. 
Lithia,  test  for,  33. 

"       in  silicates,  52. 
Lithia-tourm  aline,  135. 

MAGNESIA,  tests  for,  37,  146. 
Magnesite,  136. 
Magnetic  iron  ore,  77. 
"        pyrites,  77. 
Magnetite,  77,  117,  118. 
Malachite,  72,  121. 
Manganblende,  115,  127. 
Manganese,   test  for,  when   in 
combination,  53. 
"  ores  of,  84. 

•   "  oxide  of,  tests  for, 

156. 

Manganese-garnet,  130. 
Manganite,  117. 
Marcasite,  77,  116. 
Margarite,  131. 
Marmatite,  137. 
Mascagnine,  119. 
Matlockite,  120. 
Meerschaum,  130,  139. 
Meionite,  128. 
Melaconite,  121. 
Melanochroite,  119. 
Mellilite,  128. 
Mendipite,  120. 
Mercury,  metallic,  tests  for,  27, 

29. 
44         chlorides  of,  test  for, 

26. 

salts  of,  tests  for,  27, 53. 
44          sulphide  of,  tests  for, 

27,  53. 
44          ores  of,  86. 

oxide  of,  tests  for,  156. 
44         test  for,  in  amalgams, 

53. 

Mesolite,  128. 
Meteoric  iron,  76. 
Miargyrite,  115. 
Millerite,  88,  116. 


176 


INDEX. 


Mimetinc,  119. 
Minium,  79,  119. 
Mispickel,  78. 
Molybdenite,  118. 
Molybdenum,     compounds     of, 

test  for,  34. 

Molybdic  acid,  tests  for,  34,  156. 
Molybdine,  124. 
Monazite,  138. 
Monradite,  140. 
Muscovite,  134,  141. 
Myelin,  134. 
Mysorin,  121. 

NAGYAGITE,  114. 
Native  antimony,  114. 

arsenic,  64,  113. 

bismuth,  65,  117. 

copper,  69,  112. 

gold,  74,  112. 

iron,  112. 

lead,  112. 

mercury,  86,  112. 

palladium,  112. 

platinum,  75,  112. 

silver,  89,  112. 

sulphur,  118. 

tellurium,  114. 
Natrolite,  127. 
Natron,  125. 
Naumannite,  113. 
Neolite,  140. 
Nepheline,  128. 

Nickel,  nitrate  of,  as  reagent,  23. 
"      test  for,  when  in  combi 
nation,  54. 
"      ores  of,  87. 
"      oxide  of,  tests  for,  156. 
Nickel  glance,  88. 
Nickel  green,  89. 
Nickeliferous  gray  antimony,  88. 
Nitratine,  125. 
Nitre,  125. 

Nitric  acid,  test  for,  54. 
Nitrous  acid,     "        26. 


Nosean,  127. 

OBSIDIAN,  132. 
Ochran,  134. 
Okenite,  129. 
Olivenite,  73,  121. 
Onofrite,  113. 
Opal,  143. 
Orpiment,  65,  119. 
Orthoclase;  110,  332,  143. 
Osmium,  oxide  of,  tests  for,  158. 
Osmium-indium,  75. 
Ouvarovite,  144. 
Oxygen,  test  for,  26. 

PALLADIUM,  oxide  of,  tests 

for,  158. 
Pcarlstone,  132. 
Pectolitc,  129. 
Peganite,  133. 
Perofskite,  118. 

Peroxide  of  Nitrogen,  test  for,  26. 
Petalite,  131. 
Pharmacolite,  126. 
Phenacite,  143. 
Philippsitc,  127. 
Pholerite,  134. 
Phosphate  of  lead,  82. 
Phosphocalcite,  73,  121. 
Phosphoric  acid,  tests  for,  34,54. 
Phosphorus,  salt  of,  as  reagent, 

23. 

Pitchblende,  118,  137. 
Pitchstonc,  132. 
Pitticite,  122. 
Plagionite,  81,  115. 
Platinum,  ores  of,  75. 

"          oxide  of,  tests  for,  158. 
Plattnerite,  117. 
Pleonaste,  144. 
Plumbic  ochre,  80. 
Plumbo  resinite,  83,  133. 
Plumosite,  114. 
Polybasite,  92,  113. 
Polvcrase,  138. 


INDEX. 


177 


Polyhalite,  126. 
Polytelito,  115. 
Potash  alum,  125. 
Potassa,  tests  for,  33,  55. 

11         bi sulphate    of,  as    re 
agent,  23. 

"         oxalate  of,  as  reagent, 

36. 
Potassium,  cyanide  of,  as  reagent, 

36. 

Prehnitc,  129. 
Proustite,  91,  119.  i 
Psilomelane,  85,  lit. 
Pumice,  132. 
Purple  copper,  70,  116. 
Pyrargyriie,  91.  ; 

Pyrochlore,  142. 
Pyrolusiie,  84,  117. 
Pyromcline,  122. 
Pyromorphite,  82. 
Pyropc,  132. 
Pyrophyllite,  134. 
Pyrosclerite,  129. 
Pyrosmalite,  123. 
Pyrrhotinc,  77. 

QUARTZ,  143. 

REAGENTS,  list  of,  21,  24. ; 

Realgar,  64,  119. 

Red  antimony,  64,  119. 

Red  copper,  72,  117,  121. 

Red  lead  ore,  83. 

Red  zinc  ore,  93. 

Rhodonite,  117,  124,  130,    :fcp 

Ripidolite,  140,  141. 

Ruby  silver,  91,  119.       1  ; 

Rutil,  118,  142. 

SAL-AMMONIAC,  119. 
Salt  of  phosphorus,  as  reagent,  23. 
Samarskite,  117. 
Sassolin,  127. 
Scale  of  fusibility,  110. 
Scale  of  hardness  63. 
M 


Scapolite,  130. 

Scheeletine,  120. 

Schcelite,  131,  142. 

Schillerspar,  139. 

Scolecite,  127. 

Scorodite,  79,  122. 

Selbite,  119. 

Selenide  of  mercury,  113. 

Selcnides,  tests  for,  28,  29. 

Selenium,  tests  for,  28,  29,  31, 

34,  56. 

Selenquccksilberblei,  113. 
Serpentine,  139. 
Silicates,  behavior  of,  with  salt 

of  phosphorus,  56. 
Silicic  acid,  tests  for,  35,  56. 
Silver,  metallic,  test  for,  31. 

"      test  for,  when  in  combi 
nation,  57,  58. 

"      chloride  of,  as  reagent,  24. 

"      ores  of,  89. 

"      oxide  of,  tests  for,  158. 
Silver  glance,  90,  115. 
Skopolite,  127. 
Smaltinc,  67,  113. 
Smithsonite,  94,  135. 
Soda,  test  for,  32. 

"     carbonate  of,  as  .reagent,  24. 
Sodalite,  127. 
Spathic  iron,  78,  122. 
Specular  iron,  76. 
Sphene,  130. 
Spinel,  116,  144. 
Spodumcne,  131. 
Staurotide,  143. 
Steinmannite,  115. 
Stephanite,  91,  115. 
Sternbergite,  116. 
Stibnite,  63,  114. 
Stilbite,  129. 
Stromeyerite,  92,  116. 
Strontia,  tests  for,  146. 

"         salts  of,  test  for,  33,  36, 
Strontianite,  136. 
Sulphides,  tests  for,  28,  58. 


178 


INDEX. 


Sulphides,  distinction  of,    from 

sulphates,  58. 

Sulphur,  tests  for,  28,  29,  58. 
Sulphuretted  hydrogen,  test  for, 

26. 

Sulphurous  acid,  test  for,  26. 
Supports,  22. 
Sylvauite,  75,  114. 

TACHYLYTE,  130. 
Ta^gilite,  121. 
Talc,  141. 
Tantalite,  118. 
Tellurides,  test  for,  29. 
Telluric  bismuth,  65. 
Tellurium,  tests  for,  27,  29,  31, 

75. 

"       when  in  com 
bination,  59. 
ores  of,  114. 
Tellurous  acid,  tests  for,  27,  34, 

158. 

Tennantitc,  71,  113. 
Tenorite,  121. 

Tephroite,  127.  • 

Test-paper,  24. 
Tctradymitc,  65,  114. 
Tetrahedrite,  70,  115. 
Thcnardite,  125. 
Thomsonite,  128. 
Thorite,  138. 
Tin,  metallic,  as  reagent,  31. 

tests  for,  31,  59. 
"     ores  of,  92. 

"     oxide  of,  change  by  heat,  29. 
"       tests  for,  37,  152. 
Tin  ore,  92. 
Tin  pyrites,  93,  116. 
Titanic  acid,  tests  for,  36,  160. 
Titanic  acid,  tests  for,  when  in 

combination,  60. 
Titaniferous  iron,  78,  118. 
Topaz,  135. 
Tourmaline,  124,  131. 
Tremolite,  132. 


Triphiline,  123. 

Triplite,  122. 

Trona,  125. 

Tungstic    acid,   tests    for,    36, 

160. 

Turquois,  138. 
Tyrolite,  74,  121. 

ULLMANNITE,  88,  115. 

Uranfte,  127. 

Uranium,  test  for,  in  presence  of 

iron,  59,  GO. 
oxide  of,  tests  for,  160. 

YALENTINITE,  119. 

Yanadic  acid,  tests  for,  160. 
Yanadinite,  120. 
Yauquelinite,  83,  120 
Yivianite,  79,  123. 

WAD,  85,  137. 

Wagnerite,  127. 

Water  of  crystallization  and  hy- 

dration,  tests  for,  26. 
Wavellitc,  133. 
Webstcrite,  133. 
White  arsenic,  64 

"       iron  pyrites,  77. 

lead  ore,  81. 
Whitherite,  126. 
Willemite,  134,  136 
Wittichite,  116. 
Wffihlerite,  130. 
Wolfram,  117. 
Wolframite,  142. 
Wolfsbergitc,  115. 
Wollastonite,  128. 
Wulfenite,  84,  120. 

XANTHOCONE,  119. 
Xenotime,  143. 
Xylotile,  124,  139. 

YELLOW  LEAD  ORE  84. 

Yttria,  tests  for,  148.  • 


Yttro-cerite,  137. 
Yttro-tantalite,  118. 

ZINC,  metallic,  test  for,  31. 
"      test  for,  when  in  combi 
nation,  61. 
"      ores  of,  93. 
"      oxide     of,     change     by 
heat,  28. 


Zinc,    oxide    of,   tests    for,    37, 

162. 

Zinc  bloom,  135. 
Zincite,  93,  137. 
Zinkenite,  81,  114. 
Zippeite,  137. 
Zircon,  143. 
Zirconia,  tests  for,  148. 
Zoisite,  132. 


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